/src/samba/libcli/smb/smbXcli_base.c

Source
/*
   Unix SMB/CIFS implementation.
   Infrastructure for async SMB client requests
   Copyright (C) Volker Lendecke 2008
   Copyright (C) Stefan Metzmacher 2011

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "system/network.h"
#include "../lib/async_req/async_sock.h"
#include "../lib/util/tevent_ntstatus.h"
#include "../lib/util/tevent_unix.h"
#include "lib/tsocket/tsocket.h"
#include "source3/lib/util_tsock.h"
#include "lib/util/util_net.h"
#include "lib/util/dlinklist.h"
#include "lib/util/iov_buf.h"
#include "../libcli/smb/smb_common.h"
#include "../libcli/smb/smb_seal.h"
#include "../libcli/smb/smb_signing.h"
#include "../libcli/smb/read_smb.h"
#include "smbXcli_base.h"
#include "librpc/ndr/libndr.h"
#include "libcli/smb/smb2_negotiate_context.h"
#include "libcli/smb/smb2_signing.h"

#include "lib/crypto/gnutls_helpers.h"
#include <gnutls/gnutls.h>
#include <gnutls/crypto.h>

struct smbXcli_transport;
struct smbXcli_conn;
struct smbXcli_req;
struct smbXcli_session;
struct smbXcli_tcon;

struct smbXcli_transport {
  struct smb_transport transport;
  int sock_fd;
  struct tstream_context *tstream;
  enum tls_verify_peer_state verify_peer;
  struct samba_sockaddr laddr;
  struct samba_sockaddr raddr;

  struct tevent_req *(*writev_send_fn)(TALLOC_CTX *mem_ctx,
               struct tevent_context *ev,
               struct smbXcli_transport *xtp,
               struct tevent_queue *queue,
               struct iovec *iov,
               int count);
  ssize_t (*writev_recv_fn)(struct tevent_req *req, int *perrno);

  struct tevent_req *(*read_smb_send_fn)(TALLOC_CTX *mem_ctx,
                 struct tevent_context *ev,
                 struct smbXcli_transport *xtp);
  ssize_t (*read_smb_recv_fn)(struct tevent_req *req,
            TALLOC_CTX *mem_ctx,
            uint8_t **pbuf,
            int *perrno);

  struct tevent_req *(*monitor_send_fn)(TALLOC_CTX *mem_ctx,
                struct tevent_context *ev,
                struct smbXcli_transport *xtp);
  int (*monitor_recv_fn)(struct tevent_req *req);
};

struct smbXcli_conn {
  struct smbXcli_transport *transport;

  const char *remote_name;

  struct tevent_queue *outgoing;
  struct tevent_req **pending;
  struct tevent_req *read_smb_req;
  struct tevent_req *monitor_req;
  struct tevent_req *suicide_req;

  enum protocol_types min_protocol;
  enum protocol_types max_protocol;
  enum protocol_types protocol;
  bool allow_signing;
  bool desire_signing;
  bool mandatory_signing;

  /*
   * The incoming dispatch function should return:
   * - NT_STATUS_RETRY, if more incoming PDUs are expected.
   * - NT_STATUS_OK, if no more processing is desired, e.g.
   *                 the dispatch function called
   *                 tevent_req_done().
   * - All other return values disconnect the connection.
   */
  NTSTATUS (*dispatch_incoming)(struct smbXcli_conn *conn,
              TALLOC_CTX *tmp_mem,
              uint8_t *inbuf);

  struct {
    struct {
      uint32_t capabilities;
      uint32_t max_xmit;
    } client;

    struct {
      uint32_t capabilities;
      uint32_t max_xmit;
      uint16_t max_mux;
      uint16_t security_mode;
      bool readbraw;
      bool writebraw;
      bool lockread;
      bool writeunlock;
      uint32_t session_key;
      struct GUID guid;
      DATA_BLOB gss_blob;
      uint8_t challenge[8];
      const char *workgroup;
      const char *name;
      int time_zone;
      NTTIME system_time;
    } server;

    uint32_t capabilities;
    uint32_t max_xmit;

    uint16_t mid;

    struct smb1_signing_state *signing;
    struct smb_trans_enc_state *trans_enc;

    struct tevent_req *read_braw_req;
  } smb1;

  struct {
    struct {
      uint32_t capabilities;
      uint16_t security_mode;
      struct GUID guid;
      struct smb311_capabilities smb3_capabilities;
      bool requested_transport_level_security;
    } client;

    struct {
      uint32_t capabilities;
      uint16_t security_mode;
      struct GUID guid;
      uint32_t max_trans_size;
      uint32_t max_read_size;
      uint32_t max_write_size;
      NTTIME system_time;
      NTTIME start_time;
      DATA_BLOB gss_blob;
      uint16_t sign_algo;
      uint16_t cipher;
      bool smb311_posix;
      bool transport_trusted;
    } server;

    uint64_t mid;
    uint16_t cur_credits;
    uint16_t max_credits;

    uint32_t cc_chunk_len;
    uint32_t cc_max_chunks;

    uint8_t io_priority;

    bool force_channel_sequence;

    uint8_t preauth_sha512[64];
  } smb2;

  struct smbXcli_session *sessions;
};

struct smb2cli_session {
  uint64_t session_id;
  uint16_t session_flags;
  struct smb2_signing_key *application_key;
  struct smb2_signing_key *signing_key;
  bool should_sign;
  bool should_encrypt;
  struct smb2_signing_key *encryption_key;
  struct smb2_signing_key *decryption_key;
  uint64_t nonce_high_random;
  uint64_t nonce_high_max;
  uint64_t nonce_high;
  uint64_t nonce_low;
  uint16_t channel_sequence;
  bool replay_active;
  bool require_signed_response;

  /*
   * The following are just for torture tests
   */
  bool anonymous_signing;
  bool anonymous_encryption;
  bool no_signing_disconnect;
};

struct smbXcli_session {
  struct smbXcli_session *prev, *next;
  struct smbXcli_conn *conn;

  struct {
    uint16_t session_id;
    uint16_t action;
    DATA_BLOB application_key;
    bool protected_key;
  } smb1;

  struct smb2cli_session *smb2;

  struct {
    struct smb2_signing_key *signing_key;
    uint8_t preauth_sha512[64];
  } smb2_channel;

  /*
   * this should be a short term hack
   * until the upper layers have implemented
   * re-authentication.
   */
  bool disconnect_expired;
};

struct smbXcli_tcon {
  bool is_smb1;
  uint32_t fs_attributes;

  struct {
    uint16_t tcon_id;
    uint16_t optional_support;
    uint32_t maximal_access;
    uint32_t guest_maximal_access;
    char *service;
    char *fs_type;
  } smb1;

  struct {
    uint32_t tcon_id;
    uint8_t type;
    uint32_t flags;
    uint32_t capabilities;
    uint32_t maximal_access;
    bool should_sign;
    bool should_encrypt;
  } smb2;
};

struct smbXcli_req_state {
  struct tevent_context *ev;
  struct smbXcli_conn *conn;
  struct smbXcli_session *session; /* maybe NULL */
  struct smbXcli_tcon *tcon; /* maybe NULL */

  uint8_t length_hdr[4];

  bool one_way;

  uint8_t *inbuf;

  struct tevent_req *write_req;
  ssize_t (*writev_recv_fn)(struct tevent_req *req, int *perrno);

  struct timeval endtime;

  struct {
    /* Space for the header including the wct */
    uint8_t hdr[HDR_VWV];

    /*
     * For normal requests, smb1cli_req_send chooses a mid.
     * SecondaryV trans requests need to use the mid of the primary
     * request, so we need a place to store it.
     * Assume it is set if != 0.
     */
    uint16_t mid;

    uint16_t *vwv;
    uint8_t bytecount_buf[2];

#define MAX_SMB_IOV 10
    /* length_hdr, hdr, words, byte_count, buffers */
    struct iovec iov[1 + 3 + MAX_SMB_IOV];
    int iov_count;

    bool one_way_seqnum;
    uint32_t seqnum;
    struct tevent_req **chained_requests;

    uint8_t recv_cmd;
    NTSTATUS recv_status;
    /* always an array of 3 talloc elements */
    struct iovec *recv_iov;
  } smb1;

  struct {
    const uint8_t *fixed;
    uint16_t fixed_len;
    const uint8_t *dyn;
    uint32_t dyn_len;

    uint8_t transform[SMB2_TF_HDR_SIZE];
    uint8_t hdr[SMB2_HDR_BODY];
    uint8_t pad[7]; /* padding space for compounding */

    /*
     * always an array of 3 talloc elements
     * (without a SMB2_TRANSFORM header!)
     *
     * HDR, BODY, DYN
     */
    struct iovec *recv_iov;

    /*
     * the expected max for the response dyn_len
     */
    uint32_t max_dyn_len;

    uint16_t credit_charge;

    bool should_sign;
    bool should_encrypt;
    uint64_t encryption_session_id;

    bool signing_skipped;
    bool require_signed_response;
    bool notify_async;
    bool got_async;
    uint16_t cancel_flags;
    uint64_t cancel_mid;
    uint64_t cancel_aid;
  } smb2;
};

static int smbXcli_transport_destructor(struct smbXcli_transport *xtp)
{
  if (xtp->sock_fd != -1) {
    close(xtp->sock_fd);
    xtp->sock_fd = -1;
  }
  TALLOC_FREE(xtp->tstream);
  return 0;
}

static struct tevent_req *smbXcli_transport_tstream_writev_send(
        TALLOC_CTX *mem_ctx,
        struct tevent_context *ev,
        struct smbXcli_transport *xtp,
        struct tevent_queue *queue,
        struct iovec *iov,
        int count)
{
  return tstream_writev_queue_send(mem_ctx,
           ev,
           xtp->tstream,
           queue,
           iov,
           count);
}

static ssize_t smbXcli_transport_tstream_writev_recv(struct tevent_req *req,
             int *perrno)
{
  return tstream_writev_queue_recv(req, perrno);
}

static struct tevent_req *smbXcli_transport_tstream_read_smb_send(
        TALLOC_CTX *mem_ctx,
        struct tevent_context *ev,
        struct smbXcli_transport *xtp)
{
  return tstream_read_packet_send(mem_ctx,
          ev,
          xtp->tstream,
          4,
          read_smb_more,
          NULL);
}

static ssize_t smbXcli_transport_tstream_read_smb_recv(
        struct tevent_req *req,
        TALLOC_CTX *mem_ctx,
        uint8_t **pbuf,
        int *perrno)
{
  return tstream_read_packet_recv(req, mem_ctx, pbuf, perrno);
}

static struct tevent_req *smbXcli_transport_tstream_monitor_send(
        TALLOC_CTX *mem_ctx,
        struct tevent_context *ev,
        struct smbXcli_transport *xtp)
{
  return tstream_monitor_send(mem_ctx,
            ev,
            xtp->tstream);
}

static int smbXcli_transport_tstream_monitor_recv(struct tevent_req *req)
{
  int sys_errno = 0;
  int ret;

  ret = tstream_monitor_recv(req, &sys_errno);
  if (ret == 0) {
    sys_errno = EPIPE;
  }
  if (sys_errno == 0) {
    sys_errno = EPIPE;
  }

  return sys_errno;
}

struct smbXcli_transport *smbXcli_transport_tstream(
  TALLOC_CTX *mem_ctx,
  struct tstream_context **pstream,
  enum tls_verify_peer_state verify_peer,
  const struct samba_sockaddr *laddr,
  const struct samba_sockaddr *raddr,
  const struct smb_transport *tp)
{
  struct smbXcli_transport *xtp = NULL;

  xtp = talloc_zero(mem_ctx, struct smbXcli_transport);
  if (xtp == NULL) {
    return NULL;
  }

  xtp->transport = *tp;
  xtp->sock_fd = -1;
  xtp->verify_peer = verify_peer;

  xtp->laddr = *laddr;
  xtp->raddr = *raddr;

  xtp->tstream = talloc_move(xtp, pstream);

  xtp->writev_send_fn = smbXcli_transport_tstream_writev_send;
  xtp->writev_recv_fn = smbXcli_transport_tstream_writev_recv;
  xtp->read_smb_send_fn = smbXcli_transport_tstream_read_smb_send;
  xtp->read_smb_recv_fn = smbXcli_transport_tstream_read_smb_recv;
  xtp->monitor_send_fn = smbXcli_transport_tstream_monitor_send;
  xtp->monitor_recv_fn = smbXcli_transport_tstream_monitor_recv;

  talloc_set_destructor(xtp, smbXcli_transport_destructor);
  return xtp;
}

static struct tevent_req *smbXcli_transport_bsd_writev_send(
        TALLOC_CTX *mem_ctx,
        struct tevent_context *ev,
        struct smbXcli_transport *xtp,
        struct tevent_queue *queue,
        struct iovec *iov,
        int count)
{
  return writev_send(mem_ctx,
         ev,
         queue,
         xtp->sock_fd,
         false,
         iov,
         count);
}

static ssize_t smbXcli_transport_bsd_writev_recv(struct tevent_req *req,
             int *perrno)
{
  return writev_recv(req, perrno);
}

static struct tevent_req *smbXcli_transport_bsd_read_smb_send(
        TALLOC_CTX *mem_ctx,
        struct tevent_context *ev,
        struct smbXcli_transport *xtp)
{
  return read_smb_send(mem_ctx, ev, xtp->sock_fd);
}

static ssize_t smbXcli_transport_bsd_read_smb_recv(
        struct tevent_req *req,
        TALLOC_CTX *mem_ctx,
        uint8_t **pbuf,
        int *perrno)
{
  return read_smb_recv(req, mem_ctx, pbuf, perrno);
}

static struct tevent_req *smbXcli_transport_bsd_monitor_send(
        TALLOC_CTX *mem_ctx,
        struct tevent_context *ev,
        struct smbXcli_transport *xtp)
{
  return wait_for_error_send(mem_ctx, ev, xtp->sock_fd);
}

static int smbXcli_transport_bsd_monitor_recv(struct tevent_req *req)
{
  return wait_for_error_recv(req);
}

struct smbXcli_transport *smbXcli_transport_bsd(
  TALLOC_CTX *mem_ctx,
  int *_fd,
  enum tls_verify_peer_state verify_peer,
  const struct smb_transport *tp)
{
  struct smbXcli_transport *xtp = NULL;
  int fd = *_fd;
  int ret;

  xtp = talloc_zero(mem_ctx, struct smbXcli_transport);
  if (xtp == NULL) {
    return NULL;
  }

  xtp->transport = *tp;
  xtp->sock_fd = fd;
  xtp->verify_peer = verify_peer;

  xtp->laddr.sa_socklen = sizeof(xtp->laddr.u);
  ret = getsockname(fd, &xtp->laddr.u.sa, &xtp->laddr.sa_socklen);
  if (ret == -1) {
    TALLOC_FREE(xtp);
    return NULL;
  }

  xtp->raddr.sa_socklen = sizeof(xtp->raddr.u);
  ret = getpeername(fd, &xtp->raddr.u.sa, &xtp->raddr.sa_socklen);
  if (ret == -1) {
    TALLOC_FREE(xtp);
    return NULL;
  }

  ret = set_blocking(fd, false);
  if (ret < 0) {
    TALLOC_FREE(xtp);
    return NULL;
  }

  xtp->writev_send_fn = smbXcli_transport_bsd_writev_send;
  xtp->writev_recv_fn = smbXcli_transport_bsd_writev_recv;
  xtp->read_smb_send_fn = smbXcli_transport_bsd_read_smb_send;
  xtp->read_smb_recv_fn = smbXcli_transport_bsd_read_smb_recv;
  xtp->monitor_send_fn = smbXcli_transport_bsd_monitor_send;
  xtp->monitor_recv_fn = smbXcli_transport_bsd_monitor_recv;

  *_fd = -1;
  talloc_set_destructor(xtp, smbXcli_transport_destructor);
  return xtp;
}

struct smbXcli_transport *smbXcli_transport_bsd_tstream(
  TALLOC_CTX *mem_ctx,
  int *fd,
  enum tls_verify_peer_state verify_peer,
  const struct smb_transport *tp)
{
  struct samba_sockaddr laddr = {
    .sa_socklen = sizeof(struct sockaddr_storage),
  };
  struct samba_sockaddr raddr = {
    .sa_socklen = sizeof(struct sockaddr_storage),
  };
  struct tstream_context *tstream = NULL;
  struct smbXcli_transport *xtp = NULL;
  int ret;

  ret = getsockname(*fd, &laddr.u.sa, &laddr.sa_socklen);
  if (ret == -1) {
    return NULL;
  }

  ret = getpeername(*fd, &raddr.u.sa, &raddr.sa_socklen);
  if (ret == -1) {
    return NULL;
  }

  ret = set_blocking(*fd, false);
  if (ret < 0) {
    return NULL;
  }

  ret = tstream_bsd_existing_socket(mem_ctx, *fd, &tstream);
  if (ret == -1) {
    return NULL;
  }
  *fd = -1;
  tstream_bsd_optimize_readv(tstream, true);

  xtp = smbXcli_transport_tstream(
    mem_ctx, &tstream, verify_peer, &laddr, &raddr, tp);
  TALLOC_FREE(tstream);
  return xtp;
}

static int smbXcli_conn_destructor(struct smbXcli_conn *conn)
{
  /*
   * NT_STATUS_OK, means we do not notify the callers
   */
  smbXcli_conn_disconnect(conn, NT_STATUS_OK);

  while (conn->sessions) {
    conn->sessions->conn = NULL;
    DLIST_REMOVE(conn->sessions, conn->sessions);
  }

  if (conn->smb1.trans_enc) {
    TALLOC_FREE(conn->smb1.trans_enc);
  }

  return 0;
}

struct smbXcli_conn *smbXcli_conn_create(TALLOC_CTX *mem_ctx,
           struct smbXcli_transport **ptransport,
           const char *remote_name,
           enum smb_signing_setting signing_state,
           uint32_t smb1_capabilities,
           struct GUID *client_guid,
           uint32_t smb2_capabilities,
           const struct smb311_capabilities *smb3_capabilities)
{
  struct smbXcli_conn *conn = NULL;

  if (smb3_capabilities != NULL) {
    const struct smb3_signing_capabilities *sign_algos =
      &smb3_capabilities->signing;
    const struct smb3_encryption_capabilities *ciphers =
      &smb3_capabilities->encryption;

    SMB_ASSERT(sign_algos->num_algos <= SMB3_SIGNING_CAPABILITIES_MAX_ALGOS);
    SMB_ASSERT(ciphers->num_algos <= SMB3_ENCRYTION_CAPABILITIES_MAX_ALGOS);
  }

  conn = talloc_zero(mem_ctx, struct smbXcli_conn);
  if (!conn) {
    return NULL;
  }

  conn->transport = talloc_move(conn, ptransport);

  conn->remote_name = talloc_strdup(conn, remote_name);
  if (conn->remote_name == NULL) {
    goto error;
  }

  conn->outgoing = tevent_queue_create(conn, "smbXcli_outgoing");
  if (conn->outgoing == NULL) {
    goto error;
  }
  conn->pending = NULL;

  conn->min_protocol = PROTOCOL_NONE;
  conn->max_protocol = PROTOCOL_NONE;
  conn->protocol = PROTOCOL_NONE;

  switch (signing_state) {
  case SMB_SIGNING_OFF:
    /* never */
    conn->allow_signing = false;
    conn->desire_signing = false;
    conn->mandatory_signing = false;
    break;
  case SMB_SIGNING_DEFAULT:
  case SMB_SIGNING_IF_REQUIRED:
    /* if the server requires it */
    conn->allow_signing = true;
    conn->desire_signing = false;
    conn->mandatory_signing = false;
    break;
  case SMB_SIGNING_DESIRED:
    /* if the server desires it */
    conn->allow_signing = true;
    conn->desire_signing = true;
    conn->mandatory_signing = false;
    break;
  case SMB_SIGNING_IPC_DEFAULT:
  case SMB_SIGNING_REQUIRED:
    /* always */
    conn->allow_signing = true;
    conn->desire_signing = true;
    conn->mandatory_signing = true;
    break;
  }

  conn->smb1.client.capabilities = smb1_capabilities;
  conn->smb1.client.max_xmit = UINT16_MAX;

  conn->smb1.capabilities = conn->smb1.client.capabilities;
  conn->smb1.max_xmit = 1024;

  conn->smb1.mid = 1;

  /* initialise signing */
  conn->smb1.signing = smb1_signing_init(conn,
                conn->allow_signing,
                conn->desire_signing,
                conn->mandatory_signing);
  if (!conn->smb1.signing) {
    goto error;
  }

  conn->smb2.client.security_mode = SMB2_NEGOTIATE_SIGNING_ENABLED;
  if (conn->mandatory_signing) {
    conn->smb2.client.security_mode |= SMB2_NEGOTIATE_SIGNING_REQUIRED;
  }
  if (client_guid) {
    conn->smb2.client.guid = *client_guid;
  }
  conn->smb2.client.capabilities = smb2_capabilities;
  if (smb3_capabilities != NULL) {
    conn->smb2.client.smb3_capabilities = *smb3_capabilities;
  }

  conn->smb2.cur_credits = 1;
  conn->smb2.max_credits = 0;
  conn->smb2.io_priority = 1;

  /*
   * Samba and Windows servers accept a maximum of 16 MiB with a maximum
   * chunk length of 1 MiB.
   */
  conn->smb2.cc_chunk_len = 1024 * 1024;
  conn->smb2.cc_max_chunks = 16;

  talloc_set_destructor(conn, smbXcli_conn_destructor);
  return conn;

 error:
  TALLOC_FREE(conn);
  return NULL;
}

bool smbXcli_conn_is_connected(struct smbXcli_conn *conn)
{
  int ret;

  if (conn == NULL) {
    return false;
  }

  if (conn->transport == NULL) {
    return false;
  }

  if (conn->transport->tstream != NULL) {
    ret = tstream_pending_bytes(conn->transport->tstream);
    if (ret < 0) {
      return false;
    }

    return true;
  }

  if (conn->transport->sock_fd == -1) {
    return false;
  }

  ret = samba_socket_poll_or_sock_error(conn->transport->sock_fd);
  if (ret < 0) {
    return false;
  }

  return true;
}

enum protocol_types smbXcli_conn_protocol(struct smbXcli_conn *conn)
{
  return conn->protocol;
}

bool smbXcli_conn_use_unicode(struct smbXcli_conn *conn)
{
  if (conn->protocol >= PROTOCOL_SMB2_02) {
    return true;
  }

  if (conn->smb1.capabilities & CAP_UNICODE) {
    return true;
  }

  return false;
}

bool smbXcli_conn_signing_mandatory(struct smbXcli_conn *conn)
{
  return conn->mandatory_signing;
}

bool smbXcli_conn_have_posix(struct smbXcli_conn *conn)
{
  if (conn->protocol >= PROTOCOL_SMB3_11) {
    return conn->smb2.server.smb311_posix;
  }
  if (conn->protocol <= PROTOCOL_NT1) {
    return (conn->smb1.capabilities & CAP_UNIX);
  }
  return false;
}

/*
 * [MS-SMB] 2.2.2.3.5 - SMB1 support for passing through
 * query/set commands to the file system
 */
bool smbXcli_conn_support_passthrough(struct smbXcli_conn *conn)
{
  if (conn->protocol >= PROTOCOL_SMB2_02) {
    return true;
  }

  if (conn->smb1.capabilities & CAP_W2K_SMBS) {
    return true;
  }

  return false;
}

void smbXcli_conn_set_sockopt(struct smbXcli_conn *conn, const char *options)
{
  if (conn->transport->sock_fd == -1) {
    return;
  }

  set_socket_options(conn->transport->sock_fd, options);
}

const struct sockaddr_storage *smbXcli_conn_local_sockaddr(struct smbXcli_conn *conn)
{
  return &conn->transport->laddr.u.ss;
}

const struct sockaddr_storage *smbXcli_conn_remote_sockaddr(struct smbXcli_conn *conn)
{
  return &conn->transport->raddr.u.ss;
}

const char *smbXcli_conn_remote_name(struct smbXcli_conn *conn)
{
  return conn->remote_name;
}

uint16_t smbXcli_conn_max_requests(struct smbXcli_conn *conn)
{
  if (conn->protocol >= PROTOCOL_SMB2_02) {
    /*
     * TODO...
     */
    return 1;
  }

  return conn->smb1.server.max_mux;
}

NTTIME smbXcli_conn_server_system_time(struct smbXcli_conn *conn)
{
  if (conn->protocol >= PROTOCOL_SMB2_02) {
    return conn->smb2.server.system_time;
  }

  return conn->smb1.server.system_time;
}

const DATA_BLOB *smbXcli_conn_server_gss_blob(struct smbXcli_conn *conn)
{
  if (conn->protocol >= PROTOCOL_SMB2_02) {
    return &conn->smb2.server.gss_blob;
  }

  return &conn->smb1.server.gss_blob;
}

const struct GUID *smbXcli_conn_server_guid(struct smbXcli_conn *conn)
{
  if (conn->protocol >= PROTOCOL_SMB2_02) {
    return &conn->smb2.server.guid;
  }

  return &conn->smb1.server.guid;
}

bool smbXcli_conn_get_force_channel_sequence(struct smbXcli_conn *conn)
{
  return conn->smb2.force_channel_sequence;
}

void smbXcli_conn_set_force_channel_sequence(struct smbXcli_conn *conn,
               bool v)
{
  conn->smb2.force_channel_sequence = v;
}

struct smbXcli_conn_samba_suicide_state {
  struct smbXcli_conn *conn;
  struct iovec iov;
  uint8_t buf[9];
  struct tevent_req *write_req;
  ssize_t (*writev_recv_fn)(struct tevent_req *req, int *perrno);
};

static void smbXcli_conn_samba_suicide_cleanup(struct tevent_req *req,
                 enum tevent_req_state req_state);
static void smbXcli_conn_samba_suicide_done(struct tevent_req *subreq);

struct tevent_req *smbXcli_conn_samba_suicide_send(TALLOC_CTX *mem_ctx,
               struct tevent_context *ev,
               struct smbXcli_conn *conn,
               uint8_t exitcode)
{
  struct tevent_req *req, *subreq;
  struct smbXcli_conn_samba_suicide_state *state;
  struct smbXcli_transport *xtp = NULL;

  req = tevent_req_create(mem_ctx, &state,
        struct smbXcli_conn_samba_suicide_state);
  if (req == NULL) {
    return NULL;
  }
  state->conn = conn;
  SIVAL(state->buf, 4, SMB_SUICIDE_PACKET);
  SCVAL(state->buf, 8, exitcode);
  _smb_setlen_nbt(state->buf, sizeof(state->buf)-4);

  if (conn->suicide_req != NULL) {
    tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER);
    return tevent_req_post(req, ev);
  }

  state->iov.iov_base = state->buf;
  state->iov.iov_len = sizeof(state->buf);

  xtp = conn->transport;
  subreq = xtp->writev_send_fn(state,
             ev,
             xtp,
             conn->outgoing,
             &state->iov,
             1);
  if (tevent_req_nomem(subreq, req)) {
    return tevent_req_post(req, ev);
  }
  state->writev_recv_fn = xtp->writev_recv_fn;
  tevent_req_set_callback(subreq, smbXcli_conn_samba_suicide_done, req);
  state->write_req = subreq;

  tevent_req_set_cleanup_fn(req, smbXcli_conn_samba_suicide_cleanup);

  /*
   * We need to use tevent_req_defer_callback()
   * in order to allow smbXcli_conn_disconnect()
   * to do a safe cleanup.
   */
  tevent_req_defer_callback(req, ev);
  conn->suicide_req = req;

  return req;
}

static void smbXcli_conn_samba_suicide_cleanup(struct tevent_req *req,
                 enum tevent_req_state req_state)
{
  struct smbXcli_conn_samba_suicide_state *state = tevent_req_data(
    req, struct smbXcli_conn_samba_suicide_state);

  TALLOC_FREE(state->write_req);

  if (state->conn == NULL) {
    return;
  }

  if (state->conn->suicide_req == req) {
    state->conn->suicide_req = NULL;
  }
  state->conn = NULL;
}

static void smbXcli_conn_samba_suicide_done(struct tevent_req *subreq)
{
  struct tevent_req *req = tevent_req_callback_data(
    subreq, struct tevent_req);
  struct smbXcli_conn_samba_suicide_state *state = tevent_req_data(
    req, struct smbXcli_conn_samba_suicide_state);
  ssize_t nwritten;
  int err;

  state->write_req = NULL;

  nwritten = state->writev_recv_fn(subreq, &err);
  TALLOC_FREE(subreq);
  if (nwritten == -1) {
    /* here, we need to notify all pending requests */
    NTSTATUS status = map_nt_error_from_unix_common(err);
    smbXcli_conn_disconnect(state->conn, status);
    return;
  }
  tevent_req_done(req);
}

NTSTATUS smbXcli_conn_samba_suicide_recv(struct tevent_req *req)
{
  return tevent_req_simple_recv_ntstatus(req);
}

NTSTATUS smbXcli_conn_samba_suicide(struct smbXcli_conn *conn,
            uint8_t exitcode)
{
  TALLOC_CTX *frame = talloc_stackframe();
  struct tevent_context *ev;
  struct tevent_req *req;
  NTSTATUS status = NT_STATUS_NO_MEMORY;
  bool ok;

  if (smbXcli_conn_has_async_calls(conn)) {
    /*
     * Can't use sync call while an async call is in flight
     */
    status = NT_STATUS_INVALID_PARAMETER_MIX;
    goto fail;
  }
  ev = samba_tevent_context_init(frame);
  if (ev == NULL) {
    goto fail;
  }
  req = smbXcli_conn_samba_suicide_send(frame, ev, conn, exitcode);
  if (req == NULL) {
    goto fail;
  }
  ok = tevent_req_poll_ntstatus(req, ev, &status);
  if (!ok) {
    goto fail;
  }
  status = smbXcli_conn_samba_suicide_recv(req);
 fail:
  TALLOC_FREE(frame);
  return status;
}

uint32_t smb1cli_conn_capabilities(struct smbXcli_conn *conn)
{
  return conn->smb1.capabilities;
}

uint32_t smb1cli_conn_max_xmit(struct smbXcli_conn *conn)
{
  return conn->smb1.max_xmit;
}

bool smb1cli_conn_req_possible(struct smbXcli_conn *conn)
{
  size_t pending = talloc_array_length(conn->pending);
  uint16_t possible = conn->smb1.server.max_mux;

  if (pending >= possible) {
    return false;
  }

  return true;
}

uint32_t smb1cli_conn_server_session_key(struct smbXcli_conn *conn)
{
  return conn->smb1.server.session_key;
}

const uint8_t *smb1cli_conn_server_challenge(struct smbXcli_conn *conn)
{
  return conn->smb1.server.challenge;
}

uint16_t smb1cli_conn_server_security_mode(struct smbXcli_conn *conn)
{
  return conn->smb1.server.security_mode;
}

bool smb1cli_conn_server_readbraw(struct smbXcli_conn *conn)
{
  return conn->smb1.server.readbraw;
}

bool smb1cli_conn_server_writebraw(struct smbXcli_conn *conn)
{
  return conn->smb1.server.writebraw;
}

bool smb1cli_conn_server_lockread(struct smbXcli_conn *conn)
{
  return conn->smb1.server.lockread;
}

bool smb1cli_conn_server_writeunlock(struct smbXcli_conn *conn)
{
  return conn->smb1.server.writeunlock;
}

int smb1cli_conn_server_time_zone(struct smbXcli_conn *conn)
{
  return conn->smb1.server.time_zone;
}

bool smb1cli_conn_activate_signing(struct smbXcli_conn *conn,
           const DATA_BLOB user_session_key,
           const DATA_BLOB response)
{
  return smb1_signing_activate(conn->smb1.signing,
            user_session_key,
            response);
}

bool smb1cli_conn_check_signing(struct smbXcli_conn *conn,
        const uint8_t *buf, uint32_t seqnum)
{
  const uint8_t *hdr = buf + NBT_HDR_SIZE;
  size_t len = smb_len_nbt(buf);

  return smb1_signing_check_pdu(conn->smb1.signing, hdr, len, seqnum);
}

bool smb1cli_conn_signing_is_active(struct smbXcli_conn *conn)
{
  return smb1_signing_is_active(conn->smb1.signing);
}

void smb1cli_conn_set_encryption(struct smbXcli_conn *conn,
         struct smb_trans_enc_state *es)
{
  /* Replace the old state, if any. */
  if (conn->smb1.trans_enc) {
    TALLOC_FREE(conn->smb1.trans_enc);
  }
  conn->smb1.trans_enc = es;
}

bool smb1cli_conn_encryption_on(struct smbXcli_conn *conn)
{
  return common_encryption_on(conn->smb1.trans_enc);
}


static NTSTATUS smb1cli_pull_raw_error(const uint8_t *hdr)
{
  uint32_t flags2 = SVAL(hdr, HDR_FLG2);
  NTSTATUS status = NT_STATUS(IVAL(hdr, HDR_RCLS));

  if (NT_STATUS_IS_OK(status)) {
    return NT_STATUS_OK;
  }

  if (flags2 & FLAGS2_32_BIT_ERROR_CODES) {
    return status;
  }

  return NT_STATUS_DOS(CVAL(hdr, HDR_RCLS), SVAL(hdr, HDR_ERR));
}

/**
 * Is the SMB command able to hold an AND_X successor
 * @param[in] cmd The SMB command in question
 * @retval Can we add a chained request after "cmd"?
 */
bool smb1cli_is_andx_req(uint8_t cmd)
{
  switch (cmd) {
  case SMBtconX:
  case SMBlockingX:
  case SMBopenX:
  case SMBreadX:
  case SMBwriteX:
  case SMBsesssetupX:
  case SMBulogoffX:
  case SMBntcreateX:
    return true;
    break;
  default:
    break;
  }

  return false;
}

static uint16_t smb1cli_alloc_mid(struct smbXcli_conn *conn)
{
  size_t num_pending = talloc_array_length(conn->pending);
  uint16_t result;

  if (conn->protocol == PROTOCOL_NONE) {
    /*
     * This is what windows sends on the SMB1 Negprot request
     * and some vendors reuse the SMB1 MID as SMB2 sequence number.
     */
    return 0;
  }

  while (true) {
    size_t i;

    result = conn->smb1.mid++;
    if ((result == 0) || (result == 0xffff)) {
      continue;
    }

    for (i=0; i<num_pending; i++) {
      if (result == smb1cli_req_mid(conn->pending[i])) {
        break;
      }
    }

    if (i == num_pending) {
      return result;
    }
  }
}

static NTSTATUS smbXcli_req_cancel_write_req(struct tevent_req *req)
{
  struct smbXcli_req_state *state =
    tevent_req_data(req,
    struct smbXcli_req_state);
  struct smbXcli_conn *conn = state->conn;
  size_t num_pending = talloc_array_length(conn->pending);
  ssize_t ret;
  int err;
  bool ok;

  if (state->write_req == NULL) {
    return NT_STATUS_OK;
  }

  /*
   * Check if it's possible to cancel the request.
   * If the result is true it's not too late.
   * See writev_cancel().
   */
  ok = tevent_req_cancel(state->write_req);
  if (ok) {
    TALLOC_FREE(state->write_req);

    if (conn->protocol >= PROTOCOL_SMB2_02) {
      /*
       * SMB2 has a sane signing state.
       */
      return NT_STATUS_OK;
    }

    if (num_pending > 1) {
      /*
       * We have more pending requests following us.  This
       * means the signing state will be broken for them.
       *
       * As a solution we could add the requests directly to
       * our outgoing queue and do the signing in the trigger
       * function and then use writev_send() without passing a
       * queue.  That way we'll only sign packets we're most
       * likely send to the wire.
       */
      return NT_STATUS_REQUEST_OUT_OF_SEQUENCE;
    }

    /*
     * If we're the only request that's
     * pending, we're able to recover the signing
     * state.
     */
    smb1_signing_cancel_reply(conn->smb1.signing,
           state->smb1.one_way_seqnum);
    return NT_STATUS_OK;
  }

  ret = state->writev_recv_fn(state->write_req, &err);
  TALLOC_FREE(state->write_req);
  if (ret == -1) {
    return map_nt_error_from_unix_common(err);
  }

  return NT_STATUS_OK;
}

void smbXcli_req_unset_pending(struct tevent_req *req)
{
  struct smbXcli_req_state *state =
    tevent_req_data(req,
    struct smbXcli_req_state);
  struct smbXcli_conn *conn = state->conn;
  size_t num_pending = talloc_array_length(conn->pending);
  size_t i;
  NTSTATUS cancel_status;

  cancel_status = smbXcli_req_cancel_write_req(req);

  if (state->smb1.mid != 0) {
    /*
     * This is a [nt]trans[2] request which waits
     * for more than one reply.
     */
    if (!NT_STATUS_IS_OK(cancel_status)) {
      /*
       * If the write_req cancel didn't work
       * we can't use the connection anymore.
       */
      smbXcli_conn_disconnect(conn, cancel_status);
      return;
    }
    return;
  }

  tevent_req_set_cleanup_fn(req, NULL);

  if (num_pending == 1) {
    /*
     * The pending read_smb tevent_req is a child of
     * conn->pending. So if nothing is pending anymore, we need to
     * delete the socket read fde.
     */
    /* TODO: smbXcli_conn_cancel_read_req */
    TALLOC_FREE(conn->pending);
    conn->read_smb_req = NULL;

    if (!NT_STATUS_IS_OK(cancel_status)) {
      /*
       * If the write_req cancel didn't work
       * we can't use the connection anymore.
       */
      smbXcli_conn_disconnect(conn, cancel_status);
      return;
    }
    return;
  }

  for (i=0; i<num_pending; i++) {
    if (req == conn->pending[i]) {
      break;
    }
  }
  if (i == num_pending) {
    /*
     * Something's seriously broken. Just returning here is the
     * right thing nevertheless, the point of this routine is to
     * remove ourselves from conn->pending.
     */

    if (!NT_STATUS_IS_OK(cancel_status)) {
      /*
       * If the write_req cancel didn't work
       * we can't use the connection anymore.
       */
      smbXcli_conn_disconnect(conn, cancel_status);
      return;
    }
    return;
  }

  ARRAY_DEL_ELEMENT(conn->pending, i, num_pending);

  /*
   * No NULL check here, we're shrinking by sizeof(void *), and
   * talloc_realloc just adjusts the size for this.
   */
  conn->pending = talloc_realloc(NULL, conn->pending, struct tevent_req *,
               num_pending - 1);

  if (!NT_STATUS_IS_OK(cancel_status)) {
    /*
     * If the write_req cancel didn't work
     * we can't use the connection anymore.
     */
    smbXcli_conn_disconnect(conn, cancel_status);
    return;
  }
  return;
}

static void smbXcli_req_cleanup(struct tevent_req *req,
        enum tevent_req_state req_state)
{
  struct smbXcli_req_state *state =
    tevent_req_data(req,
    struct smbXcli_req_state);
  struct smbXcli_conn *conn = state->conn;
  NTSTATUS cancel_status;

  switch (req_state) {
  case TEVENT_REQ_RECEIVED:
    /*
     * Make sure we really remove it from
     * the pending array on destruction.
     *
     * smbXcli_req_unset_pending() calls
     * smbXcli_req_cancel_write_req() internal
     */
    state->smb1.mid = 0;
    smbXcli_req_unset_pending(req);
    return;
  default:
    cancel_status = smbXcli_req_cancel_write_req(req);
    if (!NT_STATUS_IS_OK(cancel_status)) {
      /*
       * If the write_req cancel didn't work
       * we can't use the connection anymore.
       */
      smbXcli_conn_disconnect(conn, cancel_status);
      return;
    }
    return;
  }
}

static bool smb1cli_req_cancel(struct tevent_req *req);
static bool smb2cli_req_cancel(struct tevent_req *req);

static bool smbXcli_req_cancel(struct tevent_req *req)
{
  struct smbXcli_req_state *state =
    tevent_req_data(req,
    struct smbXcli_req_state);

  if (!smbXcli_conn_is_connected(state->conn)) {
    return false;
  }

  if (state->conn->protocol == PROTOCOL_NONE) {
    return false;
  }

  if (state->conn->protocol >= PROTOCOL_SMB2_02) {
    return smb2cli_req_cancel(req);
  }

  return smb1cli_req_cancel(req);
}

static bool smbXcli_conn_receive_next(struct smbXcli_conn *conn);

bool smbXcli_req_set_pending(struct tevent_req *req)
{
  struct smbXcli_req_state *state =
    tevent_req_data(req,
    struct smbXcli_req_state);
  struct smbXcli_conn *conn = state->conn;
  struct tevent_req **pending = NULL;
  size_t num_pending = talloc_array_length(conn->pending);

  if (!smbXcli_conn_is_connected(conn)) {
    return false;
  }

  pending = talloc_realloc(conn, conn->pending, struct tevent_req *,
         num_pending+1);
  if (pending == NULL) {
    return false;
  }
  pending[num_pending] = req;
  conn->pending = pending;
  tevent_req_set_cleanup_fn(req, smbXcli_req_cleanup);
  tevent_req_set_cancel_fn(req, smbXcli_req_cancel);

  if (!smbXcli_conn_receive_next(conn)) {
    /*
     * the caller should notify the current request
     *
     * And all other pending requests get notified
     * by smbXcli_conn_disconnect().
     */
    smbXcli_req_unset_pending(req);
    smbXcli_conn_disconnect(conn, NT_STATUS_NO_MEMORY);
    return false;
  }

  return true;
}

static void smbXcli_conn_received(struct tevent_req *subreq);

static bool smbXcli_conn_receive_next(struct smbXcli_conn *conn)
{
  size_t num_pending = talloc_array_length(conn->pending);
  struct tevent_req *req;
  struct smbXcli_req_state *state;
  struct smbXcli_transport *xtp = conn->transport;

  if (conn->read_smb_req != NULL) {
    return true;
  }

  if (num_pending == 0) {
    if (conn->smb2.mid < UINT64_MAX) {
      /* no more pending requests, so we are done for now */
      return true;
    }

    /*
     * If there are no more SMB2 requests possible,
     * because we are out of message ids,
     * we need to disconnect.
     */
    smbXcli_conn_disconnect(conn, NT_STATUS_CONNECTION_ABORTED);
    return true;
  }

  req = conn->pending[0];
  state = tevent_req_data(req, struct smbXcli_req_state);

  /*
   * We're the first ones, add the read_smb request that waits for the
   * answer from the server
   */
  xtp = conn->transport;
  conn->read_smb_req = xtp->read_smb_send_fn(conn->pending,
               state->ev,
               xtp);
  if (conn->read_smb_req == NULL) {
    return false;
  }
  tevent_req_set_callback(conn->read_smb_req, smbXcli_conn_received, conn);
  return true;
}

void smbXcli_conn_disconnect(struct smbXcli_conn *conn, NTSTATUS status)
{
  struct smbXcli_session *session;
  int sock_fd = conn->transport->sock_fd;
  struct tstream_context *tstream = conn->transport->tstream;

  tevent_queue_stop(conn->outgoing);

  conn->transport->sock_fd = -1;
  conn->transport->tstream = NULL;

  session = conn->sessions;
  if (talloc_array_length(conn->pending) == 0) {
    /*
     * if we do not have pending requests
     * there is no need to update the channel_sequence
     */
    session = NULL;
  }
  for (; session; session = session->next) {
    smb2cli_session_increment_channel_sequence(session);
  }

  if (conn->monitor_req != NULL) {
    /*
     * smbXcli_conn_monitor_send()
     * used tevent_req_defer_callback() already.
     */
    if (!NT_STATUS_IS_OK(status)) {
      tevent_req_nterror(conn->monitor_req, status);
    }
    conn->monitor_req = NULL;
  }

  if (conn->suicide_req != NULL) {
    /*
     * smbXcli_conn_samba_suicide_send()
     * used tevent_req_defer_callback() already.
     */
    if (!NT_STATUS_IS_OK(status)) {
      tevent_req_nterror(conn->suicide_req, status);
    }
    conn->suicide_req = NULL;
  }

  /*
   * Cancel all pending requests. We do not do a for-loop walking
   * conn->pending because that array changes in
   * smbXcli_req_unset_pending.
   */
  while (conn->pending != NULL &&
         talloc_array_length(conn->pending) > 0) {
    struct tevent_req *req;
    struct smbXcli_req_state *state;
    struct tevent_req **chain;
    size_t num_chained;
    size_t i;

    req = conn->pending[0];
    state = tevent_req_data(req, struct smbXcli_req_state);

    if (state->smb1.chained_requests == NULL) {
      bool in_progress;

      /*
       * We're dead. No point waiting for trans2
       * replies.
       */
      state->smb1.mid = 0;

      smbXcli_req_unset_pending(req);

      if (NT_STATUS_IS_OK(status)) {
        /* do not notify the callers */
        continue;
      }

      in_progress = tevent_req_is_in_progress(req);
      if (!in_progress) {
        /*
         * already finished
         */
        continue;
      }

      /*
       * we need to defer the callback, because we may notify
       * more then one caller.
       */
      tevent_req_defer_callback(req, state->ev);
      tevent_req_nterror(req, status);
      continue;
    }

    chain = talloc_move(conn, &state->smb1.chained_requests);
    num_chained = talloc_array_length(chain);

    for (i=0; i<num_chained; i++) {
      bool in_progress;

      req = chain[i];
      state = tevent_req_data(req, struct smbXcli_req_state);

      /*
       * We're dead. No point waiting for trans2
       * replies.
       */
      state->smb1.mid = 0;

      smbXcli_req_unset_pending(req);

      if (NT_STATUS_IS_OK(status)) {
        /* do not notify the callers */
        continue;
      }

      in_progress = tevent_req_is_in_progress(req);
      if (!in_progress) {
        /*
         * already finished
         */
        continue;
      }

      /*
       * we need to defer the callback, because we may notify
       * more than one caller.
       */
      tevent_req_defer_callback(req, state->ev);
      tevent_req_nterror(req, status);
    }
    TALLOC_FREE(chain);
  }

  if (sock_fd != -1) {
    close(sock_fd);
  }
  TALLOC_FREE(tstream);
}

struct smbXcli_conn_monitor_state {
  struct smbXcli_conn *conn;
  struct tevent_req *monitor_req;
  int (*monitor_recv_fn)(struct tevent_req *req);
};

static void smbXcli_conn_monitor_cleanup(struct tevent_req *req,
           enum tevent_req_state req_state);
static void smbXcli_conn_monitor_done(struct tevent_req *subreq);

struct tevent_req *smbXcli_conn_monitor_send(TALLOC_CTX *mem_ctx,
               struct tevent_context *ev,
               struct smbXcli_conn *conn)
{
  struct tevent_req *req = NULL;
  struct smbXcli_conn_monitor_state *state = NULL;
  struct tevent_req *subreq = NULL;
  struct smbXcli_transport *xtp = NULL;
  bool ok;

  req = tevent_req_create(mem_ctx, &state,
        struct smbXcli_conn_monitor_state);
  if (req == NULL) {
    return NULL;
  }
  state->conn = conn;

  if (conn->monitor_req != NULL) {
    tevent_req_nterror(req, NT_STATUS_ALREADY_REGISTERED);
    return tevent_req_post(req, ev);
  }

  tevent_req_set_cleanup_fn(req, smbXcli_conn_monitor_cleanup);

  /*
   * We need to use tevent_req_defer_callback()
   * in order to allow smbXcli_conn_disconnect()
   * to do a safe cleanup.
   */
  tevent_req_defer_callback(req, ev);
  conn->monitor_req = req;

  ok = smbXcli_conn_is_connected(conn);
  if (!ok) {
    smbXcli_conn_disconnect(conn,
        NT_STATUS_CONNECTION_DISCONNECTED);
    return tevent_req_post(req, ev);
  }

  xtp = conn->transport;
  subreq = xtp->monitor_send_fn(state, ev, xtp);
  if (tevent_req_nomem(subreq, req)) {
    return tevent_req_post(req, ev);
  }
  state->monitor_recv_fn = xtp->monitor_recv_fn;
  tevent_req_set_callback(subreq, smbXcli_conn_monitor_done, req);
  state->monitor_req = subreq;

  return req;
}

static void smbXcli_conn_monitor_cleanup(struct tevent_req *req,
           enum tevent_req_state req_state)
{
  struct smbXcli_conn_monitor_state *state = tevent_req_data(
    req, struct smbXcli_conn_monitor_state);

  TALLOC_FREE(state->monitor_req);

  if (state->conn == NULL) {
    return;
  }

  if (state->conn->monitor_req == req) {
    state->conn->monitor_req = NULL;
  }
  state->conn = NULL;
}

static void smbXcli_conn_monitor_done(struct tevent_req *subreq)
{
  struct tevent_req *req = tevent_req_callback_data(subreq,
                struct tevent_req);
  struct smbXcli_conn_monitor_state *state = tevent_req_data(
    req, struct smbXcli_conn_monitor_state);
  NTSTATUS status;
  int err;

  state->monitor_req = NULL;

  err = state->monitor_recv_fn(subreq);
  TALLOC_FREE(subreq);
  /* here, we need to notify all pending requests */
  status = map_nt_error_from_unix_common(err);
  smbXcli_conn_disconnect(state->conn, status);
}

NTSTATUS smbXcli_conn_monitor_recv(struct tevent_req *req)
{
  return tevent_req_simple_recv_ntstatus(req);
}

NTSTATUS smbXcli_conn_monitor_once(struct smbXcli_conn *conn)
{
  TALLOC_CTX *frame = talloc_stackframe();
  struct tevent_context *ev;
  struct tevent_req *req;
  NTSTATUS status = NT_STATUS_NO_MEMORY;
  bool ok;

  if (smbXcli_conn_has_async_calls(conn)) {
    /*
     * Can't use sync call while an async call is in flight
     */
    status = NT_STATUS_INVALID_PARAMETER_MIX;
    goto fail;
  }
  ev = samba_tevent_context_init(frame);
  if (ev == NULL) {
    goto fail;
  }
  /*
   * We want tevent_req_poll()
   * to return -1 and errno=EAGAIN
   * instead of blocking in [e]poll waiting
   * for external events to happen.
   *
   * So we use tevent_context_set_wait_timeout(0)
   * that will cause tevent_loop_once() in
   * tevent_req_poll() to break with EAGAIN.
   * It also means that tevent_req_is_in_progress()
   * would still return true.
   */
  tevent_context_set_wait_timeout(ev, 0);
  req = smbXcli_conn_monitor_send(frame, ev, conn);
  if (req == NULL) {
    goto fail;
  }
  ok = tevent_req_poll(req, ev);
  if (!ok) {
    if (errno == EAGAIN) {
      /*
       * This is exactly what we want:
       * no existing events happened
       * and we avoid blocking in
       * [e]poll waiting.
       *
       * See also the comment above before
       * tevent_context_set_wait_timeout!
       *
       * We don't call smbXcli_conn_monitor_recv()
       * and let TALLOC_FREE(frame) destroy req
       * as well.
       */
      status = NT_STATUS_OK;
      goto fail;
    }
    status = map_nt_error_from_unix_common(errno);
    goto fail;
  }
  status = smbXcli_conn_monitor_recv(req);
fail:
  TALLOC_FREE(frame);
  return status;
}

/*
 * Fetch a smb request's mid. Only valid after the request has been sent by
 * smb1cli_req_send().
 */
uint16_t smb1cli_req_mid(struct tevent_req *req)
{
  struct smbXcli_req_state *state =
    tevent_req_data(req,
    struct smbXcli_req_state);

  if (state->smb1.mid != 0) {
    return state->smb1.mid;
  }

  return SVAL(state->smb1.hdr, HDR_MID);
}

void smb1cli_req_set_mid(struct tevent_req *req, uint16_t mid)
{
  struct smbXcli_req_state *state =
    tevent_req_data(req,
    struct smbXcli_req_state);

  state->smb1.mid = mid;
}

uint32_t smb1cli_req_seqnum(struct tevent_req *req)
{
  struct smbXcli_req_state *state =
    tevent_req_data(req,
    struct smbXcli_req_state);

  return state->smb1.seqnum;
}

void smb1cli_req_set_seqnum(struct tevent_req *req, uint32_t seqnum)
{
  struct smbXcli_req_state *state =
    tevent_req_data(req,
    struct smbXcli_req_state);

  state->smb1.seqnum = seqnum;
}

static size_t smbXcli_iov_len(const struct iovec *iov, int count)
{
  ssize_t ret = iov_buflen(iov, count);

  /* Ignore the overflow case for now ... */
  return ret;
}

static void smb1cli_req_flags(enum protocol_types protocol,
            uint32_t smb1_capabilities,
            uint8_t smb_command,
            uint8_t additional_flags,
            uint8_t clear_flags,
            uint8_t *_flags,
            uint16_t additional_flags2,
            uint16_t clear_flags2,
            uint16_t *_flags2)
{
  uint8_t flags = 0;
  uint16_t flags2 = 0;

  if (protocol >= PROTOCOL_LANMAN1) {
    flags |= FLAG_CASELESS_PATHNAMES;
    flags |= FLAG_CANONICAL_PATHNAMES;
  }

  if (protocol >= PROTOCOL_LANMAN2) {
    flags2 |= FLAGS2_LONG_PATH_COMPONENTS;
    flags2 |= FLAGS2_EXTENDED_ATTRIBUTES;
  }

  if (protocol >= PROTOCOL_NT1) {
    flags2 |= FLAGS2_IS_LONG_NAME;

    if (smb1_capabilities & CAP_UNICODE) {
      flags2 |= FLAGS2_UNICODE_STRINGS;
    }
    if (smb1_capabilities & CAP_STATUS32) {
      flags2 |= FLAGS2_32_BIT_ERROR_CODES;
    }
    if (smb1_capabilities & CAP_EXTENDED_SECURITY) {
      flags2 |= FLAGS2_EXTENDED_SECURITY;
    }
  }

  flags |= additional_flags;
  flags &= ~clear_flags;
  flags2 |= additional_flags2;
  flags2 &= ~clear_flags2;

  *_flags = flags;
  *_flags2 = flags2;
}

static void smb1cli_req_cancel_done(struct tevent_req *subreq);

static bool smb1cli_req_cancel(struct tevent_req *req)
{
  struct smbXcli_req_state *state =
    tevent_req_data(req,
    struct smbXcli_req_state);
  uint8_t flags;
  uint16_t flags2;
  uint32_t pid;
  uint16_t mid;
  struct tevent_req *subreq;
  NTSTATUS status;

  flags = CVAL(state->smb1.hdr, HDR_FLG);
  flags2 = SVAL(state->smb1.hdr, HDR_FLG2);
  pid  = SVAL(state->smb1.hdr, HDR_PID);
  pid |= SVAL(state->smb1.hdr, HDR_PIDHIGH)<<16;
  mid = SVAL(state->smb1.hdr, HDR_MID);

  subreq = smb1cli_req_create(state, state->ev,
            state->conn,
            SMBntcancel,
            flags, 0,
            flags2, 0,
            0, /* timeout */
            pid,
            state->tcon,
            state->session,
            0, NULL, /* vwv */
            0, NULL); /* bytes */
  if (subreq == NULL) {
    return false;
  }
  smb1cli_req_set_mid(subreq, mid);

  status = smb1cli_req_chain_submit(&subreq, 1);
  if (!NT_STATUS_IS_OK(status)) {
    TALLOC_FREE(subreq);
    return false;
  }
  smb1cli_req_set_mid(subreq, 0);

  tevent_req_set_callback(subreq, smb1cli_req_cancel_done, NULL);

  return true;
}

static void smb1cli_req_cancel_done(struct tevent_req *subreq)
{
  /* we do not care about the result */
  TALLOC_FREE(subreq);
}

struct tevent_req *smb1cli_req_create(TALLOC_CTX *mem_ctx,
              struct tevent_context *ev,
              struct smbXcli_conn *conn,
              uint8_t smb_command,
              uint8_t additional_flags,
              uint8_t clear_flags,
              uint16_t additional_flags2,
              uint16_t clear_flags2,
              uint32_t timeout_msec,
              uint32_t pid,
              struct smbXcli_tcon *tcon,
              struct smbXcli_session *session,
              uint8_t wct, uint16_t *vwv,
              int iov_count,
              struct iovec *bytes_iov)
{
  struct tevent_req *req;
  struct smbXcli_req_state *state;
  uint8_t flags = 0;
  uint16_t flags2 = 0;
  uint16_t uid = 0;
  uint16_t tid = 0;
  ssize_t num_bytes;

  if (iov_count > MAX_SMB_IOV) {
    /*
     * Should not happen :-)
     */
    return NULL;
  }

  req = tevent_req_create(mem_ctx, &state,
        struct smbXcli_req_state);
  if (req == NULL) {
    return NULL;
  }
  state->ev = ev;
  state->conn = conn;
  state->session = session;
  state->tcon = tcon;

  if (session) {
    uid = session->smb1.session_id;
  }

  if (tcon) {
    tid = tcon->smb1.tcon_id;

    if (tcon->fs_attributes & FILE_CASE_SENSITIVE_SEARCH) {
      clear_flags |= FLAG_CASELESS_PATHNAMES;
    } else {
      /* Default setting, case insensitive. */
      additional_flags |= FLAG_CASELESS_PATHNAMES;
    }

    if (smbXcli_conn_dfs_supported(conn) &&
        smbXcli_tcon_is_dfs_share(tcon))
    {
      additional_flags2 |= FLAGS2_DFS_PATHNAMES;
    }
  }

  state->smb1.recv_cmd = 0xFF;
  state->smb1.recv_status = NT_STATUS_INTERNAL_ERROR;
  state->smb1.recv_iov = talloc_zero_array(state, struct iovec, 3);
  if (state->smb1.recv_iov == NULL) {
    TALLOC_FREE(req);
    return NULL;
  }

  smb1cli_req_flags(conn->protocol,
        conn->smb1.capabilities,
        smb_command,
        additional_flags,
        clear_flags,
        &flags,
        additional_flags2,
        clear_flags2,
        &flags2);

  SIVAL(state->smb1.hdr, 0,           SMB_MAGIC);
  SCVAL(state->smb1.hdr, HDR_COM,     smb_command);
  SIVAL(state->smb1.hdr, HDR_RCLS,    NT_STATUS_V(NT_STATUS_OK));
  SCVAL(state->smb1.hdr, HDR_FLG,     flags);
  SSVAL(state->smb1.hdr, HDR_FLG2,    flags2);
  SSVAL(state->smb1.hdr, HDR_PIDHIGH, pid >> 16);
  SSVAL(state->smb1.hdr, HDR_TID,     tid);
  SSVAL(state->smb1.hdr, HDR_PID,     pid);
  SSVAL(state->smb1.hdr, HDR_UID,     uid);
  SSVAL(state->smb1.hdr, HDR_MID,     0); /* this comes later */
  SCVAL(state->smb1.hdr, HDR_WCT,     wct);

  state->smb1.vwv = vwv;

  num_bytes = iov_buflen(bytes_iov, iov_count);
  if (num_bytes == -1) {
    /*
     * I'd love to add a check for num_bytes<=UINT16_MAX here, but
     * the smbclient->samba connections can lie and transfer more.
     */
    TALLOC_FREE(req);
    return NULL;
  }

  SSVAL(state->smb1.bytecount_buf, 0, num_bytes);

  state->smb1.iov[0].iov_base = (void *)state->length_hdr;
  state->smb1.iov[0].iov_len  = sizeof(state->length_hdr);
  state->smb1.iov[1].iov_base = (void *)state->smb1.hdr;
  state->smb1.iov[1].iov_len  = sizeof(state->smb1.hdr);
  state->smb1.iov[2].iov_base = (void *)state->smb1.vwv;
  state->smb1.iov[2].iov_len  = wct * sizeof(uint16_t);
  state->smb1.iov[3].iov_base = (void *)state->smb1.bytecount_buf;
  state->smb1.iov[3].iov_len  = sizeof(uint16_t);

  if (iov_count != 0) {
    memcpy(&state->smb1.iov[4], bytes_iov,
           iov_count * sizeof(*bytes_iov));
  }
  state->smb1.iov_count = iov_count + 4;

  if (timeout_msec > 0) {
    state->endtime = timeval_current_ofs_msec(timeout_msec);
    if (!tevent_req_set_endtime(req, ev, state->endtime)) {
      return req;
    }
  }

  switch (smb_command) {
  case SMBtranss:
  case SMBtranss2:
  case SMBnttranss:
    state->one_way = true;
    break;
  case SMBntcancel:
    state->one_way = true;
    state->smb1.one_way_seqnum = true;
    break;
  case SMBlockingX:
    if ((wct == 8) &&
        (CVAL(vwv+3, 0) == LOCKING_ANDX_OPLOCK_RELEASE)) {
      state->one_way = true;
    }
    break;
  }

  return req;
}

static NTSTATUS smb1cli_conn_signv(struct smbXcli_conn *conn,
           struct iovec *iov, int iov_count,
           uint32_t *seqnum,
           bool one_way_seqnum)
{
  TALLOC_CTX *frame = NULL;
  NTSTATUS status;
  uint8_t *buf;

  /*
   * Obvious optimization: Make cli_calculate_sign_mac work with struct
   * iovec directly. MD5Update would do that just fine.
   */

  if (iov_count < 4) {
    return NT_STATUS_INVALID_PARAMETER_MIX;
  }
  if (iov[0].iov_len != NBT_HDR_SIZE) {
    return NT_STATUS_INVALID_PARAMETER_MIX;
  }
  if (iov[1].iov_len != (MIN_SMB_SIZE-sizeof(uint16_t))) {
    return NT_STATUS_INVALID_PARAMETER_MIX;
  }
  if (iov[2].iov_len > (0xFF * sizeof(uint16_t))) {
    return NT_STATUS_INVALID_PARAMETER_MIX;
  }
  if (iov[3].iov_len != sizeof(uint16_t)) {
    return NT_STATUS_INVALID_PARAMETER_MIX;
  }

  frame = talloc_stackframe();

  buf = iov_concat(frame, &iov[1], iov_count - 1);
  if (buf == NULL) {
    return NT_STATUS_NO_MEMORY;
  }

  *seqnum = smb1_signing_next_seqnum(conn->smb1.signing,
            one_way_seqnum);
  status = smb1_signing_sign_pdu(conn->smb1.signing,
              buf,
              talloc_get_size(buf),
              *seqnum);
  if (!NT_STATUS_IS_OK(status)) {
    return status;
  }
  memcpy(iov[1].iov_base, buf, iov[1].iov_len);

  TALLOC_FREE(frame);
  return NT_STATUS_OK;
}

static void smb1cli_req_writev_done(struct tevent_req *subreq);
static NTSTATUS smb1cli_conn_dispatch_incoming(struct smbXcli_conn *conn,
                 TALLOC_CTX *tmp_mem,
                 uint8_t *inbuf);

static NTSTATUS smb1cli_req_writev_submit(struct tevent_req *req,
            struct smbXcli_req_state *state,
            struct iovec *iov, int iov_count)
{
  struct smbXcli_transport *xtp = NULL;
  struct tevent_req *subreq;
  NTSTATUS status;
  uint8_t cmd;
  uint16_t mid;
  ssize_t nbtlen;

  if (!smbXcli_conn_is_connected(state->conn)) {
    return NT_STATUS_CONNECTION_DISCONNECTED;
  }

  if (state->conn->protocol > PROTOCOL_NT1) {
    DBG_ERR("called for dialect[%s] server[%s]\n",
      smb_protocol_types_string(state->conn->protocol),
      smbXcli_conn_remote_name(state->conn));
    return NT_STATUS_REVISION_MISMATCH;
  }

  if (iov_count < 4) {
    return NT_STATUS_INVALID_PARAMETER_MIX;
  }
  if (iov[0].iov_len != NBT_HDR_SIZE) {
    return NT_STATUS_INVALID_PARAMETER_MIX;
  }
  if (iov[1].iov_len != (MIN_SMB_SIZE-sizeof(uint16_t))) {
    return NT_STATUS_INVALID_PARAMETER_MIX;
  }
  if (iov[2].iov_len > (0xFF * sizeof(uint16_t))) {
    return NT_STATUS_INVALID_PARAMETER_MIX;
  }
  if (iov[3].iov_len != sizeof(uint16_t)) {
    return NT_STATUS_INVALID_PARAMETER_MIX;
  }

  cmd = CVAL(iov[1].iov_base, HDR_COM);
  if (cmd == SMBreadBraw) {
    if (smbXcli_conn_has_async_calls(state->conn)) {
      return NT_STATUS_INVALID_PARAMETER_MIX;
    }
    state->conn->smb1.read_braw_req = req;
  }

  if (state->smb1.mid != 0) {
    mid = state->smb1.mid;
  } else {
    mid = smb1cli_alloc_mid(state->conn);
  }
  SSVAL(iov[1].iov_base, HDR_MID, mid);

  nbtlen = iov_buflen(&iov[1], iov_count-1);
  if ((nbtlen == -1) || (nbtlen > 0x1FFFF)) {
    return NT_STATUS_INVALID_PARAMETER_MIX;
  }

  _smb_setlen_nbt(iov[0].iov_base, nbtlen);

  status = smb1cli_conn_signv(state->conn, iov, iov_count,
            &state->smb1.seqnum,
            state->smb1.one_way_seqnum);

  if (!NT_STATUS_IS_OK(status)) {
    return status;
  }

  /*
   * If we supported multiple encryption contexts
   * here we'd look up based on tid.
   */
  if (common_encryption_on(state->conn->smb1.trans_enc)) {
    char *buf, *enc_buf;

    buf = (char *)iov_concat(talloc_tos(), iov, iov_count);
    if (buf == NULL) {
      return NT_STATUS_NO_MEMORY;
    }
    status = common_encrypt_buffer(state->conn->smb1.trans_enc,
                 (char *)buf, &enc_buf);
    TALLOC_FREE(buf);
    if (!NT_STATUS_IS_OK(status)) {
      DEBUG(0, ("Error in encrypting client message: %s\n",
          nt_errstr(status)));
      return status;
    }
    buf = (char *)talloc_memdup(state, enc_buf,
              smb_len_nbt(enc_buf)+4);
    SAFE_FREE(enc_buf);
    if (buf == NULL) {
      return NT_STATUS_NO_MEMORY;
    }
    iov[0].iov_base = (void *)buf;
    iov[0].iov_len = talloc_get_size(buf);
    iov_count = 1;
  }

  if (state->conn->dispatch_incoming == NULL) {
    state->conn->dispatch_incoming = smb1cli_conn_dispatch_incoming;
  }

  if (!smbXcli_req_set_pending(req)) {
    return NT_STATUS_NO_MEMORY;
  }

  tevent_req_set_cancel_fn(req, smbXcli_req_cancel);

  xtp = state->conn->transport;
  subreq = xtp->writev_send_fn(state,
             state->ev,
             xtp,
             state->conn->outgoing,
             iov,
             iov_count);
  if (subreq == NULL) {
    return NT_STATUS_NO_MEMORY;
  }
  state->writev_recv_fn = xtp->writev_recv_fn;
  tevent_req_set_callback(subreq, smb1cli_req_writev_done, req);
  state->write_req = subreq;

  return NT_STATUS_OK;
}

struct tevent_req *smb1cli_req_send(TALLOC_CTX *mem_ctx,
            struct tevent_context *ev,
            struct smbXcli_conn *conn,
            uint8_t smb_command,
            uint8_t additional_flags,
            uint8_t clear_flags,
            uint16_t additional_flags2,
            uint16_t clear_flags2,
            uint32_t timeout_msec,
            uint32_t pid,
            struct smbXcli_tcon *tcon,
            struct smbXcli_session *session,
            uint8_t wct, uint16_t *vwv,
            uint32_t num_bytes,
            const uint8_t *bytes)
{
  struct tevent_req *req;
  struct iovec iov;
  NTSTATUS status;

  iov.iov_base = discard_const_p(void, bytes);
  iov.iov_len = num_bytes;

  req = smb1cli_req_create(mem_ctx, ev, conn, smb_command,
         additional_flags, clear_flags,
         additional_flags2, clear_flags2,
         timeout_msec,
         pid, tcon, session,
         wct, vwv, 1, &iov);
  if (req == NULL) {
    return NULL;
  }
  if (!tevent_req_is_in_progress(req)) {
    return tevent_req_post(req, ev);
  }
  status = smb1cli_req_chain_submit(&req, 1);
  if (tevent_req_nterror(req, status)) {
    return tevent_req_post(req, ev);
  }
  return req;
}

static void smb1cli_req_writev_done(struct tevent_req *subreq)
{
  struct tevent_req *req =
    tevent_req_callback_data(subreq,
    struct tevent_req);
  struct smbXcli_req_state *state =
    tevent_req_data(req,
    struct smbXcli_req_state);
  ssize_t nwritten;
  int err;

  state->write_req = NULL;

  nwritten = state->writev_recv_fn(subreq, &err);
  TALLOC_FREE(subreq);
  if (nwritten == -1) {
    /* here, we need to notify all pending requests */
    NTSTATUS status = map_nt_error_from_unix_common(err);
    smbXcli_conn_disconnect(state->conn, status);
    return;
  }

  if (state->one_way) {
    state->inbuf = NULL;
    tevent_req_done(req);
    return;
  }
}

static void smbXcli_conn_received(struct tevent_req *subreq)
{
  struct smbXcli_conn *conn =
    tevent_req_callback_data(subreq,
    struct smbXcli_conn);
  struct smbXcli_transport *xtp = conn->transport;
  TALLOC_CTX *frame = talloc_stackframe();
  NTSTATUS status;
  uint8_t *inbuf;
  ssize_t received;
  int err;

  if (subreq != conn->read_smb_req) {
    DEBUG(1, ("Internal error: cli_smb_received called with "
        "unexpected subreq\n"));
    smbXcli_conn_disconnect(conn, NT_STATUS_INTERNAL_ERROR);
    TALLOC_FREE(frame);
    return;
  }
  conn->read_smb_req = NULL;

  received = xtp->read_smb_recv_fn(subreq, frame, &inbuf, &err);
  TALLOC_FREE(subreq);
  if (received == -1) {
    status = map_nt_error_from_unix_common(err);
    smbXcli_conn_disconnect(conn, status);
    TALLOC_FREE(frame);
    return;
  }

  status = conn->dispatch_incoming(conn, frame, inbuf);
  TALLOC_FREE(frame);
  if (NT_STATUS_IS_OK(status)) {
    /*
     * We should not do any more processing
     * as the dispatch function called
     * tevent_req_done().
     */
    return;
  }

  if (!NT_STATUS_EQUAL(status, NT_STATUS_RETRY)) {
    /*
     * We got an error, so notify all pending requests
     */
    smbXcli_conn_disconnect(conn, status);
    return;
  }

  /*
   * We got NT_STATUS_RETRY, so we may ask for a
   * next incoming pdu.
   */
  if (!smbXcli_conn_receive_next(conn)) {
    smbXcli_conn_disconnect(conn, NT_STATUS_NO_MEMORY);
  }
}

static NTSTATUS smb1cli_inbuf_parse_chain(uint8_t *buf, TALLOC_CTX *mem_ctx,
            struct iovec **piov, int *pnum_iov)
{
  struct iovec *iov;
  size_t num_iov;
  size_t buflen;
  size_t taken;
  size_t remaining;
  uint8_t *hdr;
  uint8_t cmd;
  uint32_t wct_ofs;
  NTSTATUS status;
  size_t min_size = MIN_SMB_SIZE;

  buflen = smb_len_tcp(buf);
  taken = 0;

  hdr = buf + NBT_HDR_SIZE;

  status = smb1cli_pull_raw_error(hdr);
  if (NT_STATUS_IS_ERR(status)) {
    /*
     * This is an ugly hack to support OS/2
     * which skips the byte_count in the DATA block
     * on some error responses.
     *
     * See bug #9096
     */
    min_size -= sizeof(uint16_t);
  }

  if (buflen < min_size) {
    return NT_STATUS_INVALID_NETWORK_RESPONSE;
  }

  /*
   * This returns iovec elements in the following order:
   *
   * - SMB header
   *
   * - Parameter Block
   * - Data Block
   *
   * - Parameter Block
   * - Data Block
   *
   * - Parameter Block
   * - Data Block
   */
  num_iov = 1;

  iov = talloc_array(mem_ctx, struct iovec, num_iov);
  if (iov == NULL) {
    return NT_STATUS_NO_MEMORY;
  }
  iov[0].iov_base = hdr;
  iov[0].iov_len = HDR_WCT;
  taken += HDR_WCT;

  cmd = CVAL(hdr, HDR_COM);
  wct_ofs = HDR_WCT;

  while (true) {
    size_t len = buflen - taken;
    struct iovec *cur;
    struct iovec *iov_tmp;
    uint8_t wct;
    uint32_t bcc_ofs;
    uint16_t bcc;
    size_t needed;

    /*
     * we need at least WCT
     */
    needed = sizeof(uint8_t);
    if (len < needed) {
      DEBUG(10, ("%s: %d bytes left, expected at least %d\n",
           __location__, (int)len, (int)needed));
      goto inval;
    }

    /*
     * Now we check if the specified words are there
     */
    wct = CVAL(hdr, wct_ofs);
    needed += wct * sizeof(uint16_t);
    if (len < needed) {
      DEBUG(10, ("%s: %d bytes left, expected at least %d\n",
           __location__, (int)len, (int)needed));
      goto inval;
    }

    if ((num_iov == 1) &&
        (len == needed) &&
        NT_STATUS_IS_ERR(status))
    {
      /*
       * This is an ugly hack to support OS/2
       * which skips the byte_count in the DATA block
       * on some error responses.
       *
       * See bug #9096
       */
      iov_tmp = talloc_realloc(mem_ctx, iov, struct iovec,
             num_iov + 2);
      if (iov_tmp == NULL) {
        TALLOC_FREE(iov);
        return NT_STATUS_NO_MEMORY;
      }
      iov = iov_tmp;
      cur = &iov[num_iov];
      num_iov += 2;

      cur[0].iov_len = 0;
      cur[0].iov_base = hdr + (wct_ofs + sizeof(uint8_t));
      cur[1].iov_len = 0;
      cur[1].iov_base = cur[0].iov_base;

      taken += needed;
      break;
    }

    /*
     * we need at least BCC
     */
    needed += sizeof(uint16_t);
    if (len < needed) {
      DEBUG(10, ("%s: %d bytes left, expected at least %d\n",
           __location__, (int)len, (int)needed));
      goto inval;
    }

    /*
     * Now we check if the specified bytes are there
     */
    bcc_ofs = wct_ofs + sizeof(uint8_t) + wct * sizeof(uint16_t);
    bcc = SVAL(hdr, bcc_ofs);
    needed += bcc * sizeof(uint8_t);
    if (len < needed) {
      DEBUG(10, ("%s: %d bytes left, expected at least %d\n",
           __location__, (int)len, (int)needed));
      goto inval;
    }

    /*
     * we allocate 2 iovec structures for words and bytes
     */
    iov_tmp = talloc_realloc(mem_ctx, iov, struct iovec,
           num_iov + 2);
    if (iov_tmp == NULL) {
      TALLOC_FREE(iov);
      return NT_STATUS_NO_MEMORY;
    }
    iov = iov_tmp;
    cur = &iov[num_iov];
    num_iov += 2;

    cur[0].iov_len = wct * sizeof(uint16_t);
    cur[0].iov_base = hdr + (wct_ofs + sizeof(uint8_t));
    cur[1].iov_len = bcc * sizeof(uint8_t);
    cur[1].iov_base = hdr + (bcc_ofs + sizeof(uint16_t));

    taken += needed;

    if (!smb1cli_is_andx_req(cmd)) {
      /*
       * If the current command does not have AndX chanining
       * we are done.
       */
      break;
    }

    if (wct == 0 && bcc == 0) {
      /*
       * An empty response also ends the chain,
       * most likely with an error.
       */
      break;
    }

    if (wct < 2) {
      DEBUG(10, ("%s: wct[%d] < 2 for cmd[0x%02X]\n",
           __location__, (int)wct, (int)cmd));
      goto inval;
    }
    cmd = CVAL(cur[0].iov_base, 0);
    if (cmd == 0xFF) {
      /*
       * If it is the end of the chain we are also done.
       */
      break;
    }
    wct_ofs = SVAL(cur[0].iov_base, 2);

    if (wct_ofs < taken) {
      goto inval;
    }
    if (wct_ofs > buflen) {
      goto inval;
    }

    /*
     * we consumed everything up to the start of the next
     * parameter block.
     */
    taken = wct_ofs;
  }

  remaining = buflen - taken;

  if (remaining > 0 && num_iov >= 3) {
    /*
     * The last DATA block gets the remaining
     * bytes, this is needed to support
     * CAP_LARGE_WRITEX and CAP_LARGE_READX.
     */
    iov[num_iov-1].iov_len += remaining;
  }

  *piov = iov;
  *pnum_iov = num_iov;
  return NT_STATUS_OK;

inval:
  TALLOC_FREE(iov);
  return NT_STATUS_INVALID_NETWORK_RESPONSE;
}

static NTSTATUS smb1cli_conn_dispatch_incoming(struct smbXcli_conn *conn,
                 TALLOC_CTX *tmp_mem,
                 uint8_t *inbuf)
{
  struct tevent_req *req;
  struct smbXcli_req_state *state;
  NTSTATUS status;
  size_t num_pending;
  size_t i;
  uint8_t cmd;
  uint16_t mid;
  bool oplock_break;
  uint8_t *inhdr = inbuf + NBT_HDR_SIZE;
  size_t len = smb_len_tcp(inbuf);
  struct iovec *iov = NULL;
  int num_iov = 0;
  struct tevent_req **chain = NULL;
  size_t num_chained = 0;
  size_t num_responses = 0;

  if (conn->smb1.read_braw_req != NULL) {
    req = conn->smb1.read_braw_req;
    conn->smb1.read_braw_req = NULL;
    state = tevent_req_data(req, struct smbXcli_req_state);

    smbXcli_req_unset_pending(req);

    if (state->smb1.recv_iov == NULL) {
      /*
       * For requests with more than
       * one response, we have to readd the
       * recv_iov array.
       */
      state->smb1.recv_iov = talloc_zero_array(state,
                 struct iovec,
                 3);
      if (tevent_req_nomem(state->smb1.recv_iov, req)) {
        return NT_STATUS_OK;
      }
    }

    state->smb1.recv_iov[0].iov_base = (void *)(inhdr);
    state->smb1.recv_iov[0].iov_len = len;
    ZERO_STRUCT(state->smb1.recv_iov[1]);
    ZERO_STRUCT(state->smb1.recv_iov[2]);

    state->smb1.recv_cmd = SMBreadBraw;
    state->smb1.recv_status = NT_STATUS_OK;
    state->inbuf = talloc_move(state->smb1.recv_iov, &inbuf);

    tevent_req_done(req);
    return NT_STATUS_OK;
  }

  if ((IVAL(inhdr, 0) != SMB_MAGIC) /* 0xFF"SMB" */
      && (SVAL(inhdr, 0) != 0x45ff)) /* 0xFF"E" */ {
    DEBUG(10, ("Got non-SMB PDU\n"));
    return NT_STATUS_INVALID_NETWORK_RESPONSE;
  }

  /*
   * If we supported multiple encryption contexts
   * here we'd look up based on tid.
   */
  if (common_encryption_on(conn->smb1.trans_enc)
      && (CVAL(inbuf, 0) == 0)) {
    uint16_t enc_ctx_num;

    status = get_enc_ctx_num(inbuf, &enc_ctx_num);
    if (!NT_STATUS_IS_OK(status)) {
      DEBUG(10, ("get_enc_ctx_num returned %s\n",
           nt_errstr(status)));
      return status;
    }

    if (enc_ctx_num != conn->smb1.trans_enc->enc_ctx_num) {
      DEBUG(10, ("wrong enc_ctx %d, expected %d\n",
           enc_ctx_num,
           conn->smb1.trans_enc->enc_ctx_num));
      return NT_STATUS_INVALID_HANDLE;
    }

    status = common_decrypt_buffer(conn->smb1.trans_enc,
                 (char *)inbuf);
    if (!NT_STATUS_IS_OK(status)) {
      DEBUG(10, ("common_decrypt_buffer returned %s\n",
           nt_errstr(status)));
      return status;
    }
    inhdr = inbuf + NBT_HDR_SIZE;
    len = smb_len_nbt(inbuf);
  }

  mid = SVAL(inhdr, HDR_MID);
  num_pending = talloc_array_length(conn->pending);

  for (i=0; i<num_pending; i++) {
    if (mid == smb1cli_req_mid(conn->pending[i])) {
      break;
    }
  }
  if (i == num_pending) {
    /* Dump unexpected reply */
    return NT_STATUS_RETRY;
  }

  oplock_break = false;

  if (mid == 0xffff) {
    /*
     * Paranoia checks that this is really an oplock break request.
     */
    oplock_break = (len == 51); /* hdr + 8 words */
    oplock_break &= ((CVAL(inhdr, HDR_FLG) & FLAG_REPLY) == 0);
    oplock_break &= (CVAL(inhdr, HDR_COM) == SMBlockingX);
    oplock_break &= (SVAL(inhdr, HDR_VWV+VWV(6)) == 0);
    oplock_break &= (SVAL(inhdr, HDR_VWV+VWV(7)) == 0);

    if (!oplock_break) {
      /* Dump unexpected reply */
      return NT_STATUS_RETRY;
    }
  }

  req = conn->pending[i];
  state = tevent_req_data(req, struct smbXcli_req_state);

  if (!oplock_break /* oplock breaks are not signed */
      && !smb1_signing_check_pdu(conn->smb1.signing,
              inhdr, len, state->smb1.seqnum+1)) {
    DEBUG(10, ("cli_check_sign_mac failed\n"));
    return NT_STATUS_ACCESS_DENIED;
  }

  status = smb1cli_inbuf_parse_chain(inbuf, tmp_mem,
             &iov, &num_iov);
  if (!NT_STATUS_IS_OK(status)) {
    DEBUG(10,("smb1cli_inbuf_parse_chain - %s\n",
        nt_errstr(status)));
    return status;
  }

  cmd = CVAL(inhdr, HDR_COM);
  status = smb1cli_pull_raw_error(inhdr);

  if (NT_STATUS_EQUAL(status, NT_STATUS_NETWORK_SESSION_EXPIRED) &&
      (state->session != NULL) && state->session->disconnect_expired)
  {
    /*
     * this should be a short term hack
     * until the upper layers have implemented
     * re-authentication.
     */
    return status;
  }

  if (state->smb1.chained_requests == NULL) {
    if (num_iov != 3) {
      return NT_STATUS_INVALID_NETWORK_RESPONSE;
    }

    smbXcli_req_unset_pending(req);

    if (state->smb1.recv_iov == NULL) {
      /*
       * For requests with more than
       * one response, we have to readd the
       * recv_iov array.
       */
      state->smb1.recv_iov = talloc_zero_array(state,
                 struct iovec,
                 3);
      if (tevent_req_nomem(state->smb1.recv_iov, req)) {
        return NT_STATUS_OK;
      }
    }

    state->smb1.recv_cmd = cmd;
    state->smb1.recv_status = status;
    state->inbuf = talloc_move(state->smb1.recv_iov, &inbuf);

    state->smb1.recv_iov[0] = iov[0];
    state->smb1.recv_iov[1] = iov[1];
    state->smb1.recv_iov[2] = iov[2];

    if (talloc_array_length(conn->pending) == 0) {
      tevent_req_done(req);
      return NT_STATUS_OK;
    }

    tevent_req_defer_callback(req, state->ev);
    tevent_req_done(req);
    return NT_STATUS_RETRY;
  }

  chain = talloc_move(tmp_mem, &state->smb1.chained_requests);
  num_chained = talloc_array_length(chain);
  num_responses = (num_iov - 1)/2;

  if (num_responses > num_chained) {
    return NT_STATUS_INVALID_NETWORK_RESPONSE;
  }

  for (i=0; i<num_chained; i++) {
    size_t iov_idx = 1 + (i*2);
    struct iovec *cur = &iov[iov_idx];
    uint8_t *inbuf_ref;

    req = chain[i];
    state = tevent_req_data(req, struct smbXcli_req_state);

    smbXcli_req_unset_pending(req);

    /*
     * as we finish multiple requests here
     * we need to defer the callbacks as
     * they could destroy our current stack state.
     */
    tevent_req_defer_callback(req, state->ev);

    if (i >= num_responses) {
      tevent_req_nterror(req, NT_STATUS_REQUEST_ABORTED);
      continue;
    }

    if (state->smb1.recv_iov == NULL) {
      /*
       * For requests with more than
       * one response, we have to readd the
       * recv_iov array.
       */
      state->smb1.recv_iov = talloc_zero_array(state,
                 struct iovec,
                 3);
      if (tevent_req_nomem(state->smb1.recv_iov, req)) {
        continue;
      }
    }

    state->smb1.recv_cmd = cmd;

    if (i == (num_responses - 1)) {
      /*
       * The last request in the chain gets the status
       */
      state->smb1.recv_status = status;
    } else {
      cmd = CVAL(cur[0].iov_base, 0);
      state->smb1.recv_status = NT_STATUS_OK;
    }

    state->inbuf = inbuf;

    /*
     * Note: here we use talloc_reference() in a way
     *       that does not expose it to the caller.
     */
    inbuf_ref = talloc_reference(state->smb1.recv_iov, inbuf);
    if (tevent_req_nomem(inbuf_ref, req)) {
      continue;
    }

    /* copy the related buffers */
    state->smb1.recv_iov[0] = iov[0];
    state->smb1.recv_iov[1] = cur[0];
    state->smb1.recv_iov[2] = cur[1];

    tevent_req_done(req);
  }

  return NT_STATUS_RETRY;
}

NTSTATUS smb1cli_req_recv(struct tevent_req *req,
        TALLOC_CTX *mem_ctx,
        struct iovec **piov,
        uint8_t **phdr,
        uint8_t *pwct,
        uint16_t **pvwv,
        uint32_t *pvwv_offset,
        uint32_t *pnum_bytes,
        uint8_t **pbytes,
        uint32_t *pbytes_offset,
        uint8_t **pinbuf,
        const struct smb1cli_req_expected_response *expected,
        size_t num_expected)
{
  struct smbXcli_req_state *state =
    tevent_req_data(req,
    struct smbXcli_req_state);
  NTSTATUS status = NT_STATUS_OK;
  struct iovec *recv_iov = NULL;
  uint8_t *hdr = NULL;
  uint8_t wct = 0;
  uint32_t vwv_offset = 0;
  uint16_t *vwv = NULL;
  uint32_t num_bytes = 0;
  uint32_t bytes_offset = 0;
  uint8_t *bytes = NULL;
  size_t i;
  bool found_status = false;
  bool found_size = false;

  if (piov != NULL) {
    *piov = NULL;
  }
  if (phdr != NULL) {
    *phdr = 0;
  }
  if (pwct != NULL) {
    *pwct = 0;
  }
  if (pvwv != NULL) {
    *pvwv = NULL;
  }
  if (pvwv_offset != NULL) {
    *pvwv_offset = 0;
  }
  if (pnum_bytes != NULL) {
    *pnum_bytes = 0;
  }
  if (pbytes != NULL) {
    *pbytes = NULL;
  }
  if (pbytes_offset != NULL) {
    *pbytes_offset = 0;
  }
  if (pinbuf != NULL) {
    *pinbuf = NULL;
  }

  if (state->inbuf != NULL) {
    recv_iov = state->smb1.recv_iov;
    state->smb1.recv_iov = NULL;
    if (state->smb1.recv_cmd != SMBreadBraw) {
      hdr = (uint8_t *)recv_iov[0].iov_base;
      wct = recv_iov[1].iov_len/2;
      vwv = (uint16_t *)recv_iov[1].iov_base;
      vwv_offset = PTR_DIFF(vwv, hdr);
      num_bytes = recv_iov[2].iov_len;
      bytes = (uint8_t *)recv_iov[2].iov_base;
      bytes_offset = PTR_DIFF(bytes, hdr);
    }
  }

  if (tevent_req_is_nterror(req, &status)) {
    for (i=0; i < num_expected; i++) {
      if (NT_STATUS_EQUAL(status, expected[i].status)) {
        found_status = true;
        break;
      }
    }

    if (found_status) {
      return NT_STATUS_UNEXPECTED_NETWORK_ERROR;
    }

    return status;
  }

  if (num_expected == 0) {
    found_status = true;
    found_size = true;
  }

  status = state->smb1.recv_status;

  for (i=0; i < num_expected; i++) {
    if (!NT_STATUS_EQUAL(status, expected[i].status)) {
      continue;
    }

    found_status = true;
    if (expected[i].wct == 0) {
      found_size = true;
      break;
    }

    if (expected[i].wct == wct) {
      found_size = true;
      break;
    }
  }

  if (!found_status) {
    return status;
  }

  if (!found_size) {
    return NT_STATUS_INVALID_NETWORK_RESPONSE;
  }

  if (piov != NULL) {
    *piov = talloc_move(mem_ctx, &recv_iov);
  }

  if (phdr != NULL) {
    *phdr = hdr;
  }
  if (pwct != NULL) {
    *pwct = wct;
  }
  if (pvwv != NULL) {
    *pvwv = vwv;
  }
  if (pvwv_offset != NULL) {
    *pvwv_offset = vwv_offset;
  }
  if (pnum_bytes != NULL) {
    *pnum_bytes = num_bytes;
  }
  if (pbytes != NULL) {
    *pbytes = bytes;
  }
  if (pbytes_offset != NULL) {
    *pbytes_offset = bytes_offset;
  }
  if (pinbuf != NULL) {
    *pinbuf = state->inbuf;
  }

  return status;
}

size_t smb1cli_req_wct_ofs(struct tevent_req **reqs, int num_reqs)
{
  size_t wct_ofs;
  int i;

  wct_ofs = HDR_WCT;

  for (i=0; i<num_reqs; i++) {
    struct smbXcli_req_state *state;
    state = tevent_req_data(reqs[i], struct smbXcli_req_state);
    wct_ofs += smbXcli_iov_len(state->smb1.iov+2,
             state->smb1.iov_count-2);
    wct_ofs = (wct_ofs + 3) & ~3;
  }
  return wct_ofs;
}

NTSTATUS smb1cli_req_chain_submit(struct tevent_req **reqs, int num_reqs)
{
  struct smbXcli_req_state *first_state =
    tevent_req_data(reqs[0],
    struct smbXcli_req_state);
  struct smbXcli_req_state *state;
  size_t wct_offset;
  size_t chain_padding = 0;
  int i, iovlen;
  struct iovec *iov = NULL;
  struct iovec *this_iov;
  NTSTATUS status;
  ssize_t nbt_len;

  if (num_reqs == 1) {
    return smb1cli_req_writev_submit(reqs[0], first_state,
             first_state->smb1.iov,
             first_state->smb1.iov_count);
  }

  iovlen = 0;
  for (i=0; i<num_reqs; i++) {
    if (!tevent_req_is_in_progress(reqs[i])) {
      return NT_STATUS_INTERNAL_ERROR;
    }

    state = tevent_req_data(reqs[i], struct smbXcli_req_state);

    if (state->smb1.iov_count < 4) {
      return NT_STATUS_INVALID_PARAMETER_MIX;
    }

    if (i == 0) {
      /*
       * The NBT and SMB header
       */
      iovlen += 2;
    } else {
      /*
       * Chain padding
       */
      iovlen += 1;
    }

    /*
     * words and bytes
     */
    iovlen += state->smb1.iov_count - 2;
  }

  iov = talloc_zero_array(first_state, struct iovec, iovlen);
  if (iov == NULL) {
    return NT_STATUS_NO_MEMORY;
  }

  first_state->smb1.chained_requests = (struct tevent_req **)talloc_memdup(
    first_state, reqs, sizeof(*reqs) * num_reqs);
  if (first_state->smb1.chained_requests == NULL) {
    TALLOC_FREE(iov);
    return NT_STATUS_NO_MEMORY;
  }

  wct_offset = HDR_WCT;
  this_iov = iov;

  for (i=0; i<num_reqs; i++) {
    size_t next_padding = 0;
    uint16_t *vwv;

    state = tevent_req_data(reqs[i], struct smbXcli_req_state);

    if (i < num_reqs-1) {
      if (!smb1cli_is_andx_req(CVAL(state->smb1.hdr, HDR_COM))
          || CVAL(state->smb1.hdr, HDR_WCT) < 2) {
        TALLOC_FREE(iov);
        TALLOC_FREE(first_state->smb1.chained_requests);
        return NT_STATUS_INVALID_PARAMETER_MIX;
      }
    }

    wct_offset += smbXcli_iov_len(state->smb1.iov+2,
                state->smb1.iov_count-2) + 1;
    if ((wct_offset % 4) != 0) {
      next_padding = 4 - (wct_offset % 4);
    }
    wct_offset += next_padding;
    vwv = state->smb1.vwv;

    if (i < num_reqs-1) {
      struct smbXcli_req_state *next_state =
        tevent_req_data(reqs[i+1],
        struct smbXcli_req_state);
      SCVAL(vwv+0, 0, CVAL(next_state->smb1.hdr, HDR_COM));
      SCVAL(vwv+0, 1, 0);
      SSVAL(vwv+1, 0, wct_offset);
    } else if (smb1cli_is_andx_req(CVAL(state->smb1.hdr, HDR_COM))) {
      /* properly end the chain */
      SCVAL(vwv+0, 0, 0xff);
      SCVAL(vwv+0, 1, 0xff);
      SSVAL(vwv+1, 0, 0);
    }

    if (i == 0) {
      /*
       * The NBT and SMB header
       */
      this_iov[0] = state->smb1.iov[0];
      this_iov[1] = state->smb1.iov[1];
      this_iov += 2;
    } else {
      /*
       * This one is a bit subtle. We have to add
       * chain_padding bytes between the requests, and we
       * have to also include the wct field of the
       * subsequent requests. We use the subsequent header
       * for the padding, it contains the wct field in its
       * last byte.
       */
      this_iov[0].iov_len = chain_padding+1;
      this_iov[0].iov_base = (void *)&state->smb1.hdr[
        sizeof(state->smb1.hdr) - this_iov[0].iov_len];
      memset(this_iov[0].iov_base, 0, this_iov[0].iov_len-1);
      this_iov += 1;
    }

    /*
     * copy the words and bytes
     */
    memcpy(this_iov, state->smb1.iov+2,
           sizeof(struct iovec) * (state->smb1.iov_count-2));
    this_iov += state->smb1.iov_count - 2;
    chain_padding = next_padding;
  }

  nbt_len = iov_buflen(&iov[1], iovlen-1);
  if ((nbt_len == -1) || (nbt_len > first_state->conn->smb1.max_xmit)) {
    TALLOC_FREE(iov);
    TALLOC_FREE(first_state->smb1.chained_requests);
    return NT_STATUS_INVALID_PARAMETER_MIX;
  }

  status = smb1cli_req_writev_submit(reqs[0], first_state, iov, iovlen);
  if (!NT_STATUS_IS_OK(status)) {
    TALLOC_FREE(iov);
    TALLOC_FREE(first_state->smb1.chained_requests);
    return status;
  }

  return NT_STATUS_OK;
}

struct tevent_queue *smbXcli_conn_send_queue(struct smbXcli_conn *conn)
{
  return conn->outgoing;
}

bool smbXcli_conn_has_async_calls(struct smbXcli_conn *conn)
{
  return ((tevent_queue_length(conn->outgoing) != 0)
    || (talloc_array_length(conn->pending) != 0));
}

bool smbXcli_conn_dfs_supported(struct smbXcli_conn *conn)
{
  if (conn->protocol >= PROTOCOL_SMB2_02) {
    return (smb2cli_conn_server_capabilities(conn) & SMB2_CAP_DFS);
  }

  return (smb1cli_conn_capabilities(conn) & CAP_DFS);
}

bool smb2cli_conn_req_possible(struct smbXcli_conn *conn, uint32_t *max_dyn_len)
{
  uint16_t credits = 1;

  if (conn->smb2.cur_credits == 0) {
    if (max_dyn_len != NULL) {
      *max_dyn_len = 0;
    }
    return false;
  }

  if (conn->smb2.server.capabilities & SMB2_CAP_LARGE_MTU) {
    credits = conn->smb2.cur_credits;
  }

  if (max_dyn_len != NULL) {
    *max_dyn_len = credits * 65536;
  }

  return true;
}

uint32_t smb2cli_conn_server_capabilities(struct smbXcli_conn *conn)
{
  return conn->smb2.server.capabilities;
}

uint16_t smb2cli_conn_server_security_mode(struct smbXcli_conn *conn)
{
  return conn->smb2.server.security_mode;
}

uint16_t smb2cli_conn_server_signing_algo(struct smbXcli_conn *conn)
{
  return conn->smb2.server.sign_algo;
}

uint16_t smb2cli_conn_server_encryption_algo(struct smbXcli_conn *conn)
{
  return conn->smb2.server.cipher;
}

uint32_t smb2cli_conn_max_trans_size(struct smbXcli_conn *conn)
{
  return conn->smb2.server.max_trans_size;
}

uint32_t smb2cli_conn_max_read_size(struct smbXcli_conn *conn)
{
  return conn->smb2.server.max_read_size;
}

uint32_t smb2cli_conn_max_write_size(struct smbXcli_conn *conn)
{
  return conn->smb2.server.max_write_size;
}

void smb2cli_conn_set_max_credits(struct smbXcli_conn *conn,
          uint16_t max_credits)
{
  conn->smb2.max_credits = max_credits;
}

uint16_t smb2cli_conn_get_cur_credits(struct smbXcli_conn *conn)
{
  return conn->smb2.cur_credits;
}

uint8_t smb2cli_conn_get_io_priority(struct smbXcli_conn *conn)
{
  if (conn->protocol < PROTOCOL_SMB3_11) {
    return 0;
  }

  return conn->smb2.io_priority;
}

void smb2cli_conn_set_io_priority(struct smbXcli_conn *conn,
          uint8_t io_priority)
{
  conn->smb2.io_priority = io_priority;
}

uint32_t smb2cli_conn_cc_chunk_len(struct smbXcli_conn *conn)
{
  return conn->smb2.cc_chunk_len;
}

void smb2cli_conn_set_cc_chunk_len(struct smbXcli_conn *conn,
            uint32_t chunk_len)
{
  conn->smb2.cc_chunk_len = chunk_len;
}

uint32_t smb2cli_conn_cc_max_chunks(struct smbXcli_conn *conn)
{
  return conn->smb2.cc_max_chunks;
}

void smb2cli_conn_set_cc_max_chunks(struct smbXcli_conn *conn,
            uint32_t max_chunks)
{
  conn->smb2.cc_max_chunks = max_chunks;
}

static void smb2cli_req_cancel_done(struct tevent_req *subreq);

static bool smb2cli_req_cancel(struct tevent_req *req)
{
  struct smbXcli_req_state *state =
    tevent_req_data(req,
    struct smbXcli_req_state);
  struct smbXcli_tcon *tcon = state->tcon;
  struct smbXcli_session *session = state->session;
  uint8_t *fixed = state->smb2.pad;
  uint16_t fixed_len = 4;
  struct tevent_req *subreq;
  struct smbXcli_req_state *substate;
  NTSTATUS status;

  if (state->smb2.cancel_mid == UINT64_MAX) {
    /*
     * We already send a cancel,
     * make sure we don't do it
     * twice, otherwise we may
     * expose the same NONCE for
     * AES-128-GMAC signing
     */
    return true;
  }

  SSVAL(fixed, 0, 0x04);
  SSVAL(fixed, 2, 0);

  subreq = smb2cli_req_create(state, state->ev,
            state->conn,
            SMB2_OP_CANCEL,
            0, 0, /* flags */
            0, /* timeout */
            tcon, session,
            fixed, fixed_len,
            NULL, 0, 0);
  if (subreq == NULL) {
    return false;
  }
  substate = tevent_req_data(subreq, struct smbXcli_req_state);

  substate->smb2.cancel_mid = BVAL(state->smb2.hdr, SMB2_HDR_MESSAGE_ID);

  SIVAL(substate->smb2.hdr, SMB2_HDR_FLAGS, state->smb2.cancel_flags);
  SBVAL(substate->smb2.hdr, SMB2_HDR_MESSAGE_ID, state->smb2.cancel_mid);
  SBVAL(substate->smb2.hdr, SMB2_HDR_ASYNC_ID, state->smb2.cancel_aid);

  /*
   * remember that we don't send a cancel again
   */
  state->smb2.cancel_mid = UINT64_MAX;

  status = smb2cli_req_compound_submit(&subreq, 1);
  if (!NT_STATUS_IS_OK(status)) {
    TALLOC_FREE(subreq);
    return false;
  }

  tevent_req_set_callback(subreq, smb2cli_req_cancel_done, NULL);

  return true;
}

static void smb2cli_req_cancel_done(struct tevent_req *subreq)
{
  /* we do not care about the result */
  TALLOC_FREE(subreq);
}

struct timeval smbXcli_req_endtime(struct tevent_req *req)
{
  struct smbXcli_req_state *state = tevent_req_data(
    req, struct smbXcli_req_state);

  return state->endtime;
}

struct tevent_req *smb2cli_req_create(TALLOC_CTX *mem_ctx,
              struct tevent_context *ev,
              struct smbXcli_conn *conn,
              uint16_t cmd,
              uint32_t additional_flags,
              uint32_t clear_flags,
              uint32_t timeout_msec,
              struct smbXcli_tcon *tcon,
              struct smbXcli_session *session,
              const uint8_t *fixed,
              uint16_t fixed_len,
              const uint8_t *dyn,
              uint32_t dyn_len,
              uint32_t max_dyn_len)
{
  struct tevent_req *req;
  struct smbXcli_req_state *state;
  uint32_t flags = 0;
  uint32_t tid = 0;
  uint64_t uid = 0;
  bool use_channel_sequence = conn->smb2.force_channel_sequence;
  uint16_t channel_sequence = 0;
  bool use_replay_flag = false;
  enum protocol_types proto = smbXcli_conn_protocol(conn);

  req = tevent_req_create(mem_ctx, &state,
        struct smbXcli_req_state);
  if (req == NULL) {
    return NULL;
  }

  if ((proto > PROTOCOL_NONE) && (proto < PROTOCOL_SMB2_02)) {
    tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER);
    return req;
  }

  state->ev = ev;
  state->conn = conn;
  state->session = session;
  state->tcon = tcon;

  if (conn->smb2.server.capabilities & SMB2_CAP_PERSISTENT_HANDLES) {
    use_channel_sequence = true;
  } else if (conn->smb2.server.capabilities & SMB2_CAP_MULTI_CHANNEL) {
    use_channel_sequence = true;
  }

  if (smbXcli_conn_protocol(conn) >= PROTOCOL_SMB3_00) {
    use_replay_flag = true;
  }

  if (smbXcli_conn_protocol(conn) >= PROTOCOL_SMB3_11) {
    flags |= SMB2_PRIORITY_VALUE_TO_MASK(conn->smb2.io_priority);
  }

  if (session) {
    uid = session->smb2->session_id;

    if (use_channel_sequence) {
      channel_sequence = session->smb2->channel_sequence;
    }

    if (use_replay_flag && session->smb2->replay_active) {
      additional_flags |= SMB2_HDR_FLAG_REPLAY_OPERATION;
    }

    state->smb2.should_sign = session->smb2->should_sign;
    state->smb2.should_encrypt = session->smb2->should_encrypt;
    state->smb2.require_signed_response =
      session->smb2->require_signed_response;

    if (cmd == SMB2_OP_SESSSETUP &&
        !smb2_signing_key_valid(session->smb2_channel.signing_key) &&
        smb2_signing_key_valid(session->smb2->signing_key))
    {
      /*
       * a session bind needs to be signed
       */
      state->smb2.should_sign = true;
    }

    if (cmd == SMB2_OP_SESSSETUP &&
        !smb2_signing_key_valid(session->smb2_channel.signing_key)) {
      state->smb2.should_encrypt = false;
    }

    if (additional_flags & SMB2_HDR_FLAG_SIGNED) {
      if (!smb2_signing_key_valid(session->smb2_channel.signing_key)) {
        tevent_req_nterror(req, NT_STATUS_NO_USER_SESSION_KEY);
        return req;
      }

      additional_flags &= ~SMB2_HDR_FLAG_SIGNED;
      state->smb2.should_sign = true;
    }
  }

  if (tcon) {
    tid = tcon->smb2.tcon_id;

    if (tcon->smb2.should_sign) {
      state->smb2.should_sign = true;
    }
    if (tcon->smb2.should_encrypt) {
      state->smb2.should_encrypt = true;
    }
  }

  if (conn->smb2.server.transport_trusted) {
    /*
     * We as a client agreed with the server that quic
     * encryption is enough
     */
    state->smb2.should_encrypt = false;
  }

  if (state->smb2.should_encrypt) {
    state->smb2.should_sign = false;
  }

  state->smb2.recv_iov = talloc_zero_array(state, struct iovec, 3);
  if (tevent_req_nomem(state->smb2.recv_iov, req)) {
    return req;
  }

  flags |= additional_flags;
  flags &= ~clear_flags;

  state->smb2.fixed = fixed;
  state->smb2.fixed_len = fixed_len;
  state->smb2.dyn = dyn;
  state->smb2.dyn_len = dyn_len;
  state->smb2.max_dyn_len = max_dyn_len;

  if (state->smb2.should_encrypt) {
    SIVAL(state->smb2.transform, SMB2_TF_PROTOCOL_ID, SMB2_TF_MAGIC);
    SBVAL(state->smb2.transform, SMB2_TF_SESSION_ID, uid);
  }

  SIVAL(state->smb2.hdr, SMB2_HDR_PROTOCOL_ID, SMB2_MAGIC);
  SSVAL(state->smb2.hdr, SMB2_HDR_LENGTH,    SMB2_HDR_BODY);
  SSVAL(state->smb2.hdr, SMB2_HDR_OPCODE,    cmd);
  SSVAL(state->smb2.hdr, SMB2_HDR_CHANNEL_SEQUENCE, channel_sequence);
  SIVAL(state->smb2.hdr, SMB2_HDR_FLAGS,   flags);
  SIVAL(state->smb2.hdr, SMB2_HDR_PID,   0); /* reserved */
  SIVAL(state->smb2.hdr, SMB2_HDR_TID,   tid);
  SBVAL(state->smb2.hdr, SMB2_HDR_SESSION_ID,  uid);

  switch (cmd) {
  case SMB2_OP_CANCEL:
    state->one_way = true;
    break;
  case SMB2_OP_BREAK:
    /*
     * If this is a dummy request, it will have
     * UINT64_MAX as message id.
     * If we send on break acknowledgement,
     * this gets overwritten later.
     */
    SBVAL(state->smb2.hdr, SMB2_HDR_MESSAGE_ID, UINT64_MAX);
    break;
  }

  if (timeout_msec > 0) {
    state->endtime = timeval_current_ofs_msec(timeout_msec);
    if (!tevent_req_set_endtime(req, ev, state->endtime)) {
      return req;
    }
  }

  return req;
}

void smb2cli_req_set_notify_async(struct tevent_req *req)
{
  struct smbXcli_req_state *state =
    tevent_req_data(req,
    struct smbXcli_req_state);

  state->smb2.notify_async = true;
}

static void smb2cli_req_writev_done(struct tevent_req *subreq);
static NTSTATUS smb2cli_conn_dispatch_incoming(struct smbXcli_conn *conn,
                 TALLOC_CTX *tmp_mem,
                 uint8_t *inbuf);

NTSTATUS smb2cli_req_compound_submit(struct tevent_req **reqs,
             int num_reqs)
{
  struct smbXcli_transport *xtp = NULL;
  struct smbXcli_req_state *state;
  struct tevent_req *subreq;
  struct iovec *iov;
  int i, num_iov, nbt_len;
  int tf_iov = -1;
  struct smb2_signing_key *encryption_key = NULL;
  uint64_t encryption_session_id = 0;
  uint64_t nonce_high = UINT64_MAX;
  uint64_t nonce_low = UINT64_MAX;

  /*
   * 1 for the nbt length, optional TRANSFORM
   * per request: HDR, fixed, dyn, padding
   * -1 because the last one does not need padding
   */

  iov = talloc_array(reqs[0], struct iovec, 1 + 1 + 4*num_reqs - 1);
  if (iov == NULL) {
    return NT_STATUS_NO_MEMORY;
  }

  num_iov = 1;
  nbt_len = 0;

  /*
   * the session of the first request that requires encryption
   * specifies the encryption key.
   */
  for (i=0; i<num_reqs; i++) {
    if (!tevent_req_is_in_progress(reqs[i])) {
      return NT_STATUS_INTERNAL_ERROR;
    }

    state = tevent_req_data(reqs[i], struct smbXcli_req_state);

    if (!smbXcli_conn_is_connected(state->conn)) {
      return NT_STATUS_CONNECTION_DISCONNECTED;
    }

    if ((state->conn->protocol != PROTOCOL_NONE) &&
        (state->conn->protocol < PROTOCOL_SMB2_02)) {
      return NT_STATUS_REVISION_MISMATCH;
    }

    if (state->session == NULL) {
      continue;
    }

    if (!state->smb2.should_encrypt) {
      continue;
    }

    encryption_key = state->session->smb2->encryption_key;
    if (!smb2_signing_key_valid(encryption_key)) {
      return NT_STATUS_INVALID_PARAMETER_MIX;
    }

    encryption_session_id = state->session->smb2->session_id;

    state->session->smb2->nonce_low += 1;
    if (state->session->smb2->nonce_low == 0) {
      state->session->smb2->nonce_high += 1;
      state->session->smb2->nonce_low += 1;
    }

    /*
     * CCM and GCM algorithms must never have their
     * nonce wrap, or the security of the whole
     * communication and the keys is destroyed.
     * We must drop the connection once we have
     * transferred too much data.
     *
     * NOTE: We assume nonces greater than 8 bytes.
     */
    if (state->session->smb2->nonce_high >=
        state->session->smb2->nonce_high_max)
    {
      return NT_STATUS_ENCRYPTION_FAILED;
    }

    nonce_high = state->session->smb2->nonce_high_random;
    nonce_high += state->session->smb2->nonce_high;
    nonce_low = state->session->smb2->nonce_low;

    tf_iov = num_iov;
    iov[num_iov].iov_base = state->smb2.transform;
    iov[num_iov].iov_len  = sizeof(state->smb2.transform);
    num_iov += 1;

    SBVAL(state->smb2.transform, SMB2_TF_PROTOCOL_ID, SMB2_TF_MAGIC);
    SBVAL(state->smb2.transform, SMB2_TF_NONCE,
          nonce_low);
    SBVAL(state->smb2.transform, SMB2_TF_NONCE+8,
          nonce_high);
    SBVAL(state->smb2.transform, SMB2_TF_SESSION_ID,
          encryption_session_id);

    nbt_len += SMB2_TF_HDR_SIZE;
    break;
  }

  for (i=0; i<num_reqs; i++) {
    int hdr_iov;
    size_t reqlen;
    bool ret;
    uint16_t opcode;
    uint64_t avail;
    uint16_t charge;
    uint16_t credits;
    uint64_t mid;
    struct smb2_signing_key *signing_key = NULL;

    if (!tevent_req_is_in_progress(reqs[i])) {
      return NT_STATUS_INTERNAL_ERROR;
    }

    state = tevent_req_data(reqs[i], struct smbXcli_req_state);

    if (!smbXcli_conn_is_connected(state->conn)) {
      return NT_STATUS_CONNECTION_DISCONNECTED;
    }

    if ((state->conn->protocol != PROTOCOL_NONE) &&
        (state->conn->protocol < PROTOCOL_SMB2_02)) {
      return NT_STATUS_REVISION_MISMATCH;
    }

    opcode = SVAL(state->smb2.hdr, SMB2_HDR_OPCODE);
    if (opcode == SMB2_OP_CANCEL) {
      goto skip_credits;
    }

    avail = UINT64_MAX - state->conn->smb2.mid;
    if (avail < 1) {
      return NT_STATUS_CONNECTION_ABORTED;
    }

    if (state->conn->smb2.server.capabilities & SMB2_CAP_LARGE_MTU) {
      uint32_t max_dyn_len = 1;

      max_dyn_len = MAX(max_dyn_len, state->smb2.dyn_len);
      max_dyn_len = MAX(max_dyn_len, state->smb2.max_dyn_len);

      charge = (max_dyn_len - 1)/ 65536 + 1;
    } else {
      charge = 1;
    }

    charge = MAX(state->smb2.credit_charge, charge);

    avail = MIN(avail, state->conn->smb2.cur_credits);
    if (avail < charge) {
      DBG_ERR("Insufficient credits. "
        "%"PRIu64" available, %"PRIu16" needed\n",
        avail, charge);
      return NT_STATUS_INTERNAL_ERROR;
    }

    credits = 0;
    if (state->conn->smb2.max_credits > state->conn->smb2.cur_credits) {
      credits = state->conn->smb2.max_credits -
          state->conn->smb2.cur_credits;
    }
    if (state->conn->smb2.max_credits >= state->conn->smb2.cur_credits) {
      credits += 1;
    }

    mid = state->conn->smb2.mid;
    state->conn->smb2.mid += charge;
    state->conn->smb2.cur_credits -= charge;

    if (state->conn->smb2.server.capabilities & SMB2_CAP_LARGE_MTU) {
      SSVAL(state->smb2.hdr, SMB2_HDR_CREDIT_CHARGE, charge);
    }
    SSVAL(state->smb2.hdr, SMB2_HDR_CREDIT, credits);
    SBVAL(state->smb2.hdr, SMB2_HDR_MESSAGE_ID, mid);

    state->smb2.cancel_flags = SVAL(state->smb2.hdr, SMB2_HDR_FLAGS);
    state->smb2.cancel_flags &= ~SMB2_HDR_FLAG_CHAINED;
    if (state->conn->smb2.server.sign_algo >= SMB2_SIGNING_AES128_GMAC) {
      state->smb2.cancel_mid = mid;
    } else {
      state->smb2.cancel_mid = 0;
    }
    state->smb2.cancel_aid = 0;

skip_credits:
    if (state->session && encryption_key == NULL) {
      /*
       * We prefer the channel signing key if it is
       * already there.
       */
      if (state->smb2.should_sign) {
        signing_key = state->session->smb2_channel.signing_key;
      }

      /*
       * If it is a channel binding, we already have the main
       * signing key and try that one.
       */
      if (signing_key != NULL &&
          !smb2_signing_key_valid(signing_key)) {
        signing_key = state->session->smb2->signing_key;
      }

      /*
       * If we do not have any session key yet, we skip the
       * signing of SMB2_OP_SESSSETUP requests.
       */
      if (signing_key != NULL &&
          !smb2_signing_key_valid(signing_key)) {
        signing_key = NULL;
      }
    }

    hdr_iov = num_iov;
    iov[num_iov].iov_base = state->smb2.hdr;
    iov[num_iov].iov_len  = sizeof(state->smb2.hdr);
    num_iov += 1;

    iov[num_iov].iov_base = discard_const(state->smb2.fixed);
    iov[num_iov].iov_len  = state->smb2.fixed_len;
    num_iov += 1;

    if (state->smb2.dyn != NULL) {
      iov[num_iov].iov_base = discard_const(state->smb2.dyn);
      iov[num_iov].iov_len  = state->smb2.dyn_len;
      num_iov += 1;
    }

    reqlen  = sizeof(state->smb2.hdr);
    reqlen += state->smb2.fixed_len;
    reqlen += state->smb2.dyn_len;

    if (i < num_reqs-1) {
      if ((reqlen % 8) > 0) {
        uint8_t pad = 8 - (reqlen % 8);
        iov[num_iov].iov_base = state->smb2.pad;
        iov[num_iov].iov_len = pad;
        num_iov += 1;
        reqlen += pad;
      }
      SIVAL(state->smb2.hdr, SMB2_HDR_NEXT_COMMAND, reqlen);
    }

    state->smb2.encryption_session_id = encryption_session_id;

    if (signing_key != NULL) {
      NTSTATUS status;

      status = smb2_signing_sign_pdu(signing_key,
                   &iov[hdr_iov], num_iov - hdr_iov);
      if (!NT_STATUS_IS_OK(status)) {
        return status;
      }
    }

    nbt_len += reqlen;

    ret = smbXcli_req_set_pending(reqs[i]);
    if (!ret) {
      return NT_STATUS_NO_MEMORY;
    }
  }

  state = tevent_req_data(reqs[0], struct smbXcli_req_state);
  _smb_setlen_tcp(state->length_hdr, nbt_len);
  iov[0].iov_base = state->length_hdr;
  iov[0].iov_len  = sizeof(state->length_hdr);

  if (encryption_key != NULL) {
    NTSTATUS status;
    size_t buflen = nbt_len - SMB2_TF_HDR_SIZE;
    uint8_t *buf;
    int vi;

    buf = talloc_array(iov, uint8_t, buflen);
    if (buf == NULL) {
      return NT_STATUS_NO_MEMORY;
    }

    /*
     * We copy the buffers before encrypting them,
     * this is at least currently needed for the
     * to keep state->smb2.hdr.
     *
     * Also the callers may expect there buffers
     * to be const.
     */
    for (vi = tf_iov + 1; vi < num_iov; vi++) {
      struct iovec *v = &iov[vi];
      const uint8_t *o = (const uint8_t *)v->iov_base;

      memcpy(buf, o, v->iov_len);
      v->iov_base = (void *)buf;
      buf += v->iov_len;
    }

    status = smb2_signing_encrypt_pdu(encryption_key,
          &iov[tf_iov], num_iov - tf_iov);
    if (!NT_STATUS_IS_OK(status)) {
      return status;
    }
  }

  if (state->conn->dispatch_incoming == NULL) {
    state->conn->dispatch_incoming = smb2cli_conn_dispatch_incoming;
  }

  xtp = state->conn->transport;
  subreq = xtp->writev_send_fn(state,
             state->ev,
             xtp,
             state->conn->outgoing,
             iov,
             num_iov);
  if (subreq == NULL) {
    return NT_STATUS_NO_MEMORY;
  }
  state->writev_recv_fn = xtp->writev_recv_fn;
  tevent_req_set_callback(subreq, smb2cli_req_writev_done, reqs[0]);
  state->write_req = subreq;

  return NT_STATUS_OK;
}

void smb2cli_req_set_credit_charge(struct tevent_req *req, uint16_t charge)
{
  struct smbXcli_req_state *state =
    tevent_req_data(req,
    struct smbXcli_req_state);

  state->smb2.credit_charge = charge;
}

struct tevent_req *smb2cli_req_send(TALLOC_CTX *mem_ctx,
            struct tevent_context *ev,
            struct smbXcli_conn *conn,
            uint16_t cmd,
            uint32_t additional_flags,
            uint32_t clear_flags,
            uint32_t timeout_msec,
            struct smbXcli_tcon *tcon,
            struct smbXcli_session *session,
            const uint8_t *fixed,
            uint16_t fixed_len,
            const uint8_t *dyn,
            uint32_t dyn_len,
            uint32_t max_dyn_len)
{
  struct tevent_req *req;
  NTSTATUS status;

  req = smb2cli_req_create(mem_ctx, ev, conn, cmd,
         additional_flags, clear_flags,
         timeout_msec,
         tcon, session,
         fixed, fixed_len,
         dyn, dyn_len,
         max_dyn_len);
  if (req == NULL) {
    return NULL;
  }
  if (!tevent_req_is_in_progress(req)) {
    return tevent_req_post(req, ev);
  }
  status = smb2cli_req_compound_submit(&req, 1);
  if (tevent_req_nterror(req, status)) {
    return tevent_req_post(req, ev);
  }
  return req;
}

static void smb2cli_req_writev_done(struct tevent_req *subreq)
{
  struct tevent_req *req =
    tevent_req_callback_data(subreq,
    struct tevent_req);
  struct smbXcli_req_state *state =
    tevent_req_data(req,
    struct smbXcli_req_state);
  ssize_t nwritten;
  int err;

  state->write_req = NULL;

  nwritten = state->writev_recv_fn(subreq, &err);
  TALLOC_FREE(subreq);
  if (nwritten == -1) {
    /* here, we need to notify all pending requests */
    NTSTATUS status = map_nt_error_from_unix_common(err);
    smbXcli_conn_disconnect(state->conn, status);
    return;
  }
}

static struct smbXcli_session* smbXcli_session_by_uid(struct smbXcli_conn *conn,
                 uint64_t uid)
{
  struct smbXcli_session *s = conn->sessions;

  for (; s; s = s->next) {
    if (s->smb2->session_id != uid) {
      continue;
    }
    break;
  }

  return s;
}

static NTSTATUS smb2cli_inbuf_parse_compound(struct smbXcli_conn *conn,
               uint8_t *buf,
               size_t buflen,
               TALLOC_CTX *mem_ctx,
               struct iovec **piov,
               size_t *pnum_iov)
{
  struct iovec *iov;
  int num_iov = 0;
  size_t taken = 0;
  uint8_t *first_hdr = buf;
  size_t verified_buflen = 0;
  uint8_t *tf = NULL;
  size_t tf_len = 0;

  iov = talloc_array(mem_ctx, struct iovec, num_iov);
  if (iov == NULL) {
    return NT_STATUS_NO_MEMORY;
  }

  while (taken < buflen) {
    size_t len = buflen - taken;
    uint8_t *hdr = first_hdr + taken;
    struct iovec *cur;
    size_t full_size;
    size_t next_command_ofs;
    uint16_t body_size;
    struct iovec *iov_tmp;

    if (verified_buflen > taken) {
      len = verified_buflen - taken;
    } else {
      tf = NULL;
      tf_len = 0;
    }

    if (len < 4) {
      DEBUG(10, ("%d bytes left, expected at least %d\n",
           (int)len, 4));
      goto inval;
    }
    if (IVAL(hdr, 0) == SMB2_TF_MAGIC) {
      struct smbXcli_session *s;
      uint64_t uid;
      struct iovec tf_iov[2];
      size_t enc_len;
      NTSTATUS status;

      if (len < SMB2_TF_HDR_SIZE) {
        DEBUG(10, ("%d bytes left, expected at least %d\n",
             (int)len, SMB2_TF_HDR_SIZE));
        goto inval;
      }
      tf = hdr;
      tf_len = SMB2_TF_HDR_SIZE;
      taken += tf_len;

      hdr = first_hdr + taken;
      enc_len = IVAL(tf, SMB2_TF_MSG_SIZE);
      uid = BVAL(tf, SMB2_TF_SESSION_ID);

      if (len < SMB2_TF_HDR_SIZE + enc_len) {
        DEBUG(10, ("%d bytes left, expected at least %d\n",
             (int)len,
             (int)(SMB2_TF_HDR_SIZE + enc_len)));
        goto inval;
      }

      s = smbXcli_session_by_uid(conn, uid);
      if (s == NULL) {
        DEBUG(10, ("unknown session_id %llu\n",
             (unsigned long long)uid));
        goto inval;
      }

      tf_iov[0].iov_base = (void *)tf;
      tf_iov[0].iov_len = tf_len;
      tf_iov[1].iov_base = (void *)hdr;
      tf_iov[1].iov_len = enc_len;

      status = smb2_signing_decrypt_pdu(s->smb2->decryption_key,
                tf_iov, 2);
      if (!NT_STATUS_IS_OK(status)) {
        TALLOC_FREE(iov);
        return status;
      }

      verified_buflen = taken + enc_len;
      len = enc_len;
    }

    /*
     * We need the header plus the body length field
     */

    if (len < SMB2_HDR_BODY + 2) {
      DEBUG(10, ("%d bytes left, expected at least %d\n",
           (int)len, SMB2_HDR_BODY));
      goto inval;
    }
    if (IVAL(hdr, 0) != SMB2_MAGIC) {
      DEBUG(10, ("Got non-SMB2 PDU: %x\n",
           IVAL(hdr, 0)));
      goto inval;
    }
    if (SVAL(hdr, 4) != SMB2_HDR_BODY) {
      DEBUG(10, ("Got HDR len %d, expected %d\n",
           SVAL(hdr, 4), SMB2_HDR_BODY));
      goto inval;
    }

    full_size = len;
    next_command_ofs = IVAL(hdr, SMB2_HDR_NEXT_COMMAND);
    body_size = SVAL(hdr, SMB2_HDR_BODY);

    if (next_command_ofs != 0) {
      if (next_command_ofs < (SMB2_HDR_BODY + 2)) {
        goto inval;
      }
      if (next_command_ofs > full_size) {
        goto inval;
      }
      full_size = next_command_ofs;
    }
    if (body_size < 2) {
      goto inval;
    }
    body_size &= 0xfffe;

    if (body_size > (full_size - SMB2_HDR_BODY)) {
      goto inval;
    }

    iov_tmp = talloc_realloc(mem_ctx, iov, struct iovec,
           num_iov + 4);
    if (iov_tmp == NULL) {
      TALLOC_FREE(iov);
      return NT_STATUS_NO_MEMORY;
    }
    iov = iov_tmp;
    cur = &iov[num_iov];
    num_iov += 4;

    cur[0].iov_base = tf;
    cur[0].iov_len  = tf_len;
    cur[1].iov_base = hdr;
    cur[1].iov_len  = SMB2_HDR_BODY;
    cur[2].iov_base = hdr + SMB2_HDR_BODY;
    cur[2].iov_len  = body_size;
    cur[3].iov_base = hdr + SMB2_HDR_BODY + body_size;
    cur[3].iov_len  = full_size - (SMB2_HDR_BODY + body_size);

    taken += full_size;
  }

  *piov = iov;
  *pnum_iov = num_iov;
  return NT_STATUS_OK;

inval:
  TALLOC_FREE(iov);
  return NT_STATUS_INVALID_NETWORK_RESPONSE;
}

static struct tevent_req *smb2cli_conn_find_pending(struct smbXcli_conn *conn,
                uint64_t mid)
{
  size_t num_pending = talloc_array_length(conn->pending);
  size_t i;

  for (i=0; i<num_pending; i++) {
    struct tevent_req *req = conn->pending[i];
    struct smbXcli_req_state *state =
      tevent_req_data(req,
      struct smbXcli_req_state);

    if (mid == BVAL(state->smb2.hdr, SMB2_HDR_MESSAGE_ID)) {
      return req;
    }
  }
  return NULL;
}

static NTSTATUS smb2cli_conn_dispatch_incoming(struct smbXcli_conn *conn,
                 TALLOC_CTX *tmp_mem,
                 uint8_t *inbuf)
{
  struct tevent_req *req;
  struct smbXcli_req_state *state = NULL;
  struct iovec *iov = NULL;
  size_t i, num_iov = 0;
  NTSTATUS status;
  bool defer = true;
  struct smbXcli_session *last_session = NULL;
  size_t inbuf_len = smb_len_tcp(inbuf);

  status = smb2cli_inbuf_parse_compound(conn,
                inbuf + NBT_HDR_SIZE,
                inbuf_len,
                tmp_mem,
                &iov, &num_iov);
  if (!NT_STATUS_IS_OK(status)) {
    return status;
  }

  for (i=0; i<num_iov; i+=4) {
    uint8_t *inbuf_ref = NULL;
    struct iovec *cur = &iov[i];
    uint8_t *inhdr = (uint8_t *)cur[1].iov_base;
    uint16_t opcode = SVAL(inhdr, SMB2_HDR_OPCODE);
    uint32_t flags = IVAL(inhdr, SMB2_HDR_FLAGS);
    uint64_t mid = BVAL(inhdr, SMB2_HDR_MESSAGE_ID);
    uint16_t req_opcode;
    uint32_t req_flags;
    uint16_t credits = SVAL(inhdr, SMB2_HDR_CREDIT);
    uint32_t new_credits;
    struct smbXcli_session *session = NULL;
    struct smb2_signing_key *signing_key = NULL;
    bool was_encrypted = false;

    new_credits = conn->smb2.cur_credits;
    new_credits += credits;
    if (new_credits > UINT16_MAX) {
      return NT_STATUS_INVALID_NETWORK_RESPONSE;
    }
    conn->smb2.cur_credits += credits;

    req = smb2cli_conn_find_pending(conn, mid);
    if (req == NULL) {
      return NT_STATUS_INVALID_NETWORK_RESPONSE;
    }
    state = tevent_req_data(req, struct smbXcli_req_state);

    req_opcode = SVAL(state->smb2.hdr, SMB2_HDR_OPCODE);
    if (opcode != req_opcode) {
      return NT_STATUS_INVALID_NETWORK_RESPONSE;
    }
    req_flags = SVAL(state->smb2.hdr, SMB2_HDR_FLAGS);

    if (!(flags & SMB2_HDR_FLAG_REDIRECT)) {
      return NT_STATUS_INVALID_NETWORK_RESPONSE;
    }

    status = NT_STATUS(IVAL(inhdr, SMB2_HDR_STATUS));
    if ((flags & SMB2_HDR_FLAG_ASYNC) &&
        NT_STATUS_EQUAL(status, NT_STATUS_PENDING)) {
      uint64_t async_id = BVAL(inhdr, SMB2_HDR_ASYNC_ID);

      if (state->smb2.got_async) {
        /* We only expect one STATUS_PENDING response */
        return NT_STATUS_INVALID_NETWORK_RESPONSE;
      }
      state->smb2.got_async = true;

      /*
       * async interim responses are not signed,
       * even if the SMB2_HDR_FLAG_SIGNED flag
       * is set.
       */
      state->smb2.cancel_flags |= SMB2_HDR_FLAG_ASYNC;
      state->smb2.cancel_aid = async_id;

      if (state->smb2.notify_async) {
        tevent_req_defer_callback(req, state->ev);
        tevent_req_notify_callback(req);
      }
      continue;
    }

    session = state->session;
    if (req_flags & SMB2_HDR_FLAG_CHAINED) {
      session = last_session;
    }
    last_session = session;

    if (flags & SMB2_HDR_FLAG_SIGNED) {
      uint64_t uid = BVAL(inhdr, SMB2_HDR_SESSION_ID);

      if (session == NULL) {
        session = smbXcli_session_by_uid(state->conn,
                 uid);
      }

      if (session == NULL) {
        return NT_STATUS_INVALID_NETWORK_RESPONSE;
      }

      last_session = session;
      signing_key = session->smb2_channel.signing_key;
    }

    if (opcode == SMB2_OP_SESSSETUP) {
      /*
       * We prefer the channel signing key, if it is
       * already there.
       *
       * If we do not have a channel signing key yet,
       * we try the main signing key, if it is not
       * the final response.
       */
      if (signing_key != NULL &&
          !smb2_signing_key_valid(signing_key) &&
          !NT_STATUS_IS_OK(status)) {
        signing_key = session->smb2->signing_key;
      }

      if (signing_key != NULL &&
          !smb2_signing_key_valid(signing_key)) {
        /*
         * If we do not have a session key to
         * verify the signature, we defer the
         * signing check to the caller.
         *
         * The caller gets NT_STATUS_OK, it
         * has to call
         * smb2cli_session_set_session_key()
         * or
         * smb2cli_session_set_channel_key()
         * which will check the signature
         * with the channel signing key.
         */
        signing_key = NULL;
      }

      if (!NT_STATUS_IS_OK(status)) {
        /*
         * Only check the signature of the last response
         * of a successful session auth. This matches
         * Windows behaviour for NTLM auth and reauth.
         */
        state->smb2.require_signed_response = false;
      }
    }

    if (state->smb2.should_sign ||
        state->smb2.require_signed_response)
    {
      if (!(flags & SMB2_HDR_FLAG_SIGNED)) {
        return NT_STATUS_ACCESS_DENIED;
      }
    }

    if (!smb2_signing_key_valid(signing_key) &&
        state->smb2.require_signed_response) {
      signing_key = session->smb2_channel.signing_key;
    }

    if (cur[0].iov_len == SMB2_TF_HDR_SIZE) {
      const uint8_t *tf = (const uint8_t *)cur[0].iov_base;
      uint64_t uid = BVAL(tf, SMB2_TF_SESSION_ID);

      /*
       * If the response was encrypted in a SMB2_TRANSFORM
       * pdu, which belongs to the correct session,
       * we do not need to do signing checks
       *
       * It could be the session the response belongs to
       * or the session that was used to encrypt the
       * SMB2_TRANSFORM request.
       */
      if ((session && session->smb2->session_id == uid) ||
          (state->smb2.encryption_session_id == uid)) {
        signing_key = NULL;
        was_encrypted = true;
      }
    }

    if (NT_STATUS_EQUAL(status, NT_STATUS_USER_SESSION_DELETED)) {
      /*
       * if the server returns NT_STATUS_USER_SESSION_DELETED
       * the response is not signed and we should
       * propagate the NT_STATUS_USER_SESSION_DELETED
       * status to the caller.
       */
      state->smb2.signing_skipped = true;
      signing_key = NULL;
    }
    if (NT_STATUS_EQUAL(status, NT_STATUS_REQUEST_OUT_OF_SEQUENCE)) {
      /*
       * if the server returns
       * NT_STATUS_REQUEST_OUT_OF_SEQUENCE for a session setup
       * request, the response is not signed and we should
       * propagate the NT_STATUS_REQUEST_OUT_OF_SEQUENCE
       * status to the caller
       */
      if (opcode == SMB2_OP_SESSSETUP) {
        state->smb2.signing_skipped = true;
        signing_key = NULL;
      }
    }
    if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_SUPPORTED)) {
      /*
       * if the server returns NT_STATUS_NOT_SUPPORTED
       * for a session setup request, the response is not
       * signed and we should propagate the NT_STATUS_NOT_SUPPORTED
       * status to the caller.
       */
      if (opcode == SMB2_OP_SESSSETUP) {
        state->smb2.signing_skipped = true;
        signing_key = NULL;
      }
    }
    if (NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED)) {
      /*
       * if the server returns
       * NT_STATUS_ACCESS_DENIED for a session setup
       * request, the response is not signed and we should
       * propagate the NT_STATUS_ACCESS_DENIED
       * status to the caller without disconnecting
       * the connection because we where not able to
       * verify the response signature.
       */
      if (opcode == SMB2_OP_SESSSETUP) {
        state->smb2.signing_skipped = true;
        signing_key = NULL;
      }
    }

    if (NT_STATUS_EQUAL(status, NT_STATUS_INVALID_PARAMETER)) {
      /*
       * if the server returns
       * NT_STATUS_INVALID_PARAMETER
       * the response might not be encrypted.
       */
      if (state->smb2.should_encrypt && !was_encrypted) {
        state->smb2.signing_skipped = true;
        signing_key = NULL;
      }
    }

    if (state->smb2.should_encrypt && !was_encrypted) {
      if (!state->smb2.signing_skipped) {
        return NT_STATUS_ACCESS_DENIED;
      }
    }

    if (NT_STATUS_EQUAL(status, NT_STATUS_NETWORK_NAME_DELETED) ||
        NT_STATUS_EQUAL(status, NT_STATUS_FILE_CLOSED) ||
        (NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED) &&
         session != NULL &&
         session->smb2->no_signing_disconnect) ||
        NT_STATUS_EQUAL(status, NT_STATUS_INVALID_PARAMETER)) {
      /*
       * if the server returns
       * NT_STATUS_NETWORK_NAME_DELETED
       * NT_STATUS_FILE_CLOSED
       * NT_STATUS_INVALID_PARAMETER
       * the response might not be signed
       * as this happens before the signing checks.
       *
       * If server echos the signature (or all zeros)
       * we should report the status from the server
       * to the caller.
       */
      if (signing_key) {
        bool cmp;

        cmp = mem_equal_const_time(inhdr+SMB2_HDR_SIGNATURE,
                 state->smb2.hdr+SMB2_HDR_SIGNATURE,
                 16);
        if (cmp) {
          state->smb2.signing_skipped = true;
          signing_key = NULL;
        }
      }
      if (signing_key) {
        bool zero;
        zero = all_zero(inhdr+SMB2_HDR_SIGNATURE, 16);
        if (zero) {
          state->smb2.signing_skipped = true;
          signing_key = NULL;
        }
      }
    }

    if (signing_key) {
      NTSTATUS signing_status;

      signing_status = smb2_signing_check_pdu(signing_key,
                &cur[1], 3);
      if (!NT_STATUS_IS_OK(signing_status)) {
        /*
         * If the signing check fails, we disconnect
         * the connection.
         *
         * Unless
         * smb2cli_session_torture_no_signing_disconnect
         * was called in torture tests
         */

        if (!NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED)) {
          return signing_status;
        }

        if (!NT_STATUS_EQUAL(status, signing_status)) {
          return signing_status;
        }

        if (session == NULL) {
          return signing_status;
        }

        if (!session->smb2->no_signing_disconnect) {
          return signing_status;
        }

        state->smb2.signing_skipped = true;
      }
    }

    if (NT_STATUS_EQUAL(status, NT_STATUS_NETWORK_SESSION_EXPIRED) &&
        (session != NULL) && session->disconnect_expired)
    {
      /*
       * this should be a short term hack
       * until the upper layers have implemented
       * re-authentication.
       */
      return status;
    }

    smbXcli_req_unset_pending(req);

    /*
     * There might be more than one response
     * we need to defer the notifications
     */
    if ((num_iov == 5) && (talloc_array_length(conn->pending) == 0)) {
      defer = false;
    }

    if (defer) {
      tevent_req_defer_callback(req, state->ev);
    }

    /*
     * Note: here we use talloc_reference() in a way
     *       that does not expose it to the caller.
     */
    inbuf_ref = talloc_reference(state->smb2.recv_iov, inbuf);
    if (tevent_req_nomem(inbuf_ref, req)) {
      continue;
    }

    /* copy the related buffers */
    state->smb2.recv_iov[0] = cur[1];
    state->smb2.recv_iov[1] = cur[2];
    state->smb2.recv_iov[2] = cur[3];

    tevent_req_done(req);
  }

  if (defer) {
    return NT_STATUS_RETRY;
  }

  return NT_STATUS_OK;
}

NTSTATUS smb2cli_req_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
        struct iovec **piov,
        const struct smb2cli_req_expected_response *expected,
        size_t num_expected)
{
  struct smbXcli_req_state *state =
    tevent_req_data(req,
    struct smbXcli_req_state);
  NTSTATUS status;
  size_t body_size;
  bool found_status = false;
  bool found_size = false;
  size_t i;

  if (piov != NULL) {
    *piov = NULL;
  }

  if (tevent_req_is_in_progress(req) && state->smb2.got_async) {
    return NT_STATUS_PENDING;
  }

  if (tevent_req_is_nterror(req, &status)) {
    for (i=0; i < num_expected; i++) {
      if (NT_STATUS_EQUAL(status, expected[i].status)) {
        return NT_STATUS_UNEXPECTED_NETWORK_ERROR;
      }
    }

    return status;
  }

  if (num_expected == 0) {
    found_status = true;
    found_size = true;
  }

  status = NT_STATUS(IVAL(state->smb2.recv_iov[0].iov_base, SMB2_HDR_STATUS));
  body_size = SVAL(state->smb2.recv_iov[1].iov_base, 0);

  for (i=0; i < num_expected; i++) {
    if (!NT_STATUS_EQUAL(status, expected[i].status)) {
      continue;
    }

    found_status = true;
    if (expected[i].body_size == 0) {
      found_size = true;
      break;
    }

    if (expected[i].body_size == body_size) {
      found_size = true;
      break;
    }
  }

  if (!found_status) {
    return status;
  }

  if (state->smb2.signing_skipped) {
    if (num_expected > 0) {
      return NT_STATUS_ACCESS_DENIED;
    }
    if (!NT_STATUS_IS_ERR(status)) {
      return NT_STATUS_ACCESS_DENIED;
    }
  }

  if (!found_size) {
    return NT_STATUS_INVALID_NETWORK_RESPONSE;
  }

  if (piov != NULL) {
    *piov = talloc_move(mem_ctx, &state->smb2.recv_iov);
  }

  return status;
}

NTSTATUS smb2cli_req_get_sent_iov(struct tevent_req *req,
          struct iovec *sent_iov)
{
  struct smbXcli_req_state *state =
    tevent_req_data(req,
    struct smbXcli_req_state);

  if (tevent_req_is_in_progress(req)) {
    return NT_STATUS_PENDING;
  }

  sent_iov[0].iov_base = state->smb2.hdr;
  sent_iov[0].iov_len  = sizeof(state->smb2.hdr);

  sent_iov[1].iov_base = discard_const(state->smb2.fixed);
  sent_iov[1].iov_len  = state->smb2.fixed_len;

  if (state->smb2.dyn != NULL) {
    sent_iov[2].iov_base = discard_const(state->smb2.dyn);
    sent_iov[2].iov_len  = state->smb2.dyn_len;
  } else {
    sent_iov[2].iov_base = NULL;
    sent_iov[2].iov_len  = 0;
  }

  return NT_STATUS_OK;
}

static const struct {
  enum protocol_types proto;
  const char smb1_name[24]; /* strlen("MICROSOFT NETWORKS 1.03") == 23 */
} smb1cli_prots[] = {
  {PROTOCOL_CORE,   "PC NETWORK PROGRAM 1.0"},
  {PROTOCOL_COREPLUS, "MICROSOFT NETWORKS 1.03"},
  {PROTOCOL_LANMAN1,  "MICROSOFT NETWORKS 3.0"},
  {PROTOCOL_LANMAN1,  "LANMAN1.0"},
  {PROTOCOL_LANMAN2,  "LM1.2X002"},
  {PROTOCOL_LANMAN2,  "DOS LANMAN2.1"},
  {PROTOCOL_LANMAN2,  "LANMAN2.1"},
  {PROTOCOL_LANMAN2,  "Samba"},
  {PROTOCOL_NT1,    "NT LANMAN 1.0"},
  {PROTOCOL_NT1,    "NT LM 0.12"},
  {PROTOCOL_SMB2_02,  "SMB 2.002"},
  {PROTOCOL_SMB2_10,  "SMB 2.???"},
};

static const struct {
  enum protocol_types proto;
  uint16_t smb2_dialect;
} smb2cli_prots[] = {
  {PROTOCOL_SMB2_02,  SMB2_DIALECT_REVISION_202},
  {PROTOCOL_SMB2_10,  SMB2_DIALECT_REVISION_210},
  {PROTOCOL_SMB3_00,  SMB3_DIALECT_REVISION_300},
  {PROTOCOL_SMB3_02,  SMB3_DIALECT_REVISION_302},
  {PROTOCOL_SMB3_11,  SMB3_DIALECT_REVISION_311},
};

struct smbXcli_negprot_state {
  struct smbXcli_conn *conn;
  struct tevent_context *ev;
  struct smb2_negotiate_contexts *in_ctx;
  struct smb2_negotiate_contexts *out_ctx;
  uint32_t timeout_msec;

  struct {
    uint8_t fixed[36];
  } smb2;
};

static void smbXcli_negprot_invalid_done(struct tevent_req *subreq);
static struct tevent_req *smbXcli_negprot_smb1_subreq(struct smbXcli_negprot_state *state);
static void smbXcli_negprot_smb1_done(struct tevent_req *subreq);
static struct tevent_req *smbXcli_negprot_smb2_subreq(struct smbXcli_negprot_state *state);
static void smbXcli_negprot_smb2_done(struct tevent_req *subreq);
static NTSTATUS smbXcli_negprot_dispatch_incoming(struct smbXcli_conn *conn,
              TALLOC_CTX *frame,
              uint8_t *inbuf);

struct tevent_req *smbXcli_negprot_send(TALLOC_CTX *mem_ctx,
          struct tevent_context *ev,
          struct smbXcli_conn *conn,
          uint32_t timeout_msec,
          enum protocol_types min_protocol,
          enum protocol_types max_protocol,
          uint16_t max_credits,
          struct smb2_negotiate_contexts *in_ctx)
{
  struct tevent_req *req, *subreq;
  struct smbXcli_negprot_state *state;

  req = tevent_req_create(mem_ctx, &state,
        struct smbXcli_negprot_state);
  if (req == NULL) {
    return NULL;
  }
  state->conn = conn;
  state->ev = ev;
  state->in_ctx = in_ctx;
  state->timeout_msec = timeout_msec;

  if (min_protocol == PROTOCOL_NONE) {
    tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER_MIX);
    return tevent_req_post(req, ev);
  }

  if (max_protocol == PROTOCOL_NONE) {
    tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER_MIX);
    return tevent_req_post(req, ev);
  }

  if (min_protocol > max_protocol) {
    tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER_MIX);
    return tevent_req_post(req, ev);
  }

  conn->min_protocol = min_protocol;
  conn->max_protocol = max_protocol;
  conn->protocol = PROTOCOL_NONE;

  if (max_protocol >= PROTOCOL_SMB2_02) {
    conn->smb2.max_credits = max_credits;
  }

  if ((min_protocol < PROTOCOL_SMB2_02) &&
      (max_protocol < PROTOCOL_SMB2_02)) {
    /*
     * SMB1 only...
     */
    conn->dispatch_incoming = smb1cli_conn_dispatch_incoming;

    subreq = smbXcli_negprot_smb1_subreq(state);
    if (tevent_req_nomem(subreq, req)) {
      return tevent_req_post(req, ev);
    }
    tevent_req_set_callback(subreq, smbXcli_negprot_smb1_done, req);
    return req;
  }

  if ((min_protocol >= PROTOCOL_SMB2_02) &&
      (max_protocol >= PROTOCOL_SMB2_02)) {
    /*
     * SMB2 only...
     */
    conn->dispatch_incoming = smb2cli_conn_dispatch_incoming;

    subreq = smbXcli_negprot_smb2_subreq(state);
    if (tevent_req_nomem(subreq, req)) {
      return tevent_req_post(req, ev);
    }
    tevent_req_set_callback(subreq, smbXcli_negprot_smb2_done, req);
    return req;
  }

  /*
   * We send an SMB1 negprot with the SMB2 dialects
   * and expect a SMB1 or a SMB2 response.
   *
   * smbXcli_negprot_dispatch_incoming() will fix the
   * callback to match protocol of the response.
   */
  conn->dispatch_incoming = smbXcli_negprot_dispatch_incoming;

  subreq = smbXcli_negprot_smb1_subreq(state);
  if (tevent_req_nomem(subreq, req)) {
    return tevent_req_post(req, ev);
  }
  tevent_req_set_callback(subreq, smbXcli_negprot_invalid_done, req);
  return req;
}

static void smbXcli_negprot_invalid_done(struct tevent_req *subreq)
{
  struct tevent_req *req =
    tevent_req_callback_data(subreq,
    struct tevent_req);
  NTSTATUS status;

  /*
   * we just want the low level error
   */
  status = tevent_req_simple_recv_ntstatus(subreq);
  TALLOC_FREE(subreq);
  if (tevent_req_nterror(req, status)) {
    return;
  }

  /* this should never happen */
  tevent_req_nterror(req, NT_STATUS_INTERNAL_ERROR);
}

static struct tevent_req *smbXcli_negprot_smb1_subreq(struct smbXcli_negprot_state *state)
{
  size_t i;
  DATA_BLOB bytes = data_blob_null;
  uint8_t flags;
  uint16_t flags2;

  /* setup the protocol strings */
  for (i=0; i < ARRAY_SIZE(smb1cli_prots); i++) {
    uint8_t c = 2;
    bool ok;

    if (smb1cli_prots[i].proto < state->conn->min_protocol) {
      continue;
    }

    if (smb1cli_prots[i].proto > state->conn->max_protocol) {
      continue;
    }

    ok = data_blob_append(state, &bytes, &c, sizeof(c));
    if (!ok) {
      return NULL;
    }

    /*
     * We know it is already ascii and
     * we want NULL termination.
     */
    ok = data_blob_append(state, &bytes,
              smb1cli_prots[i].smb1_name,
              strlen(smb1cli_prots[i].smb1_name)+1);
    if (!ok) {
      return NULL;
    }
  }

  smb1cli_req_flags(state->conn->max_protocol,
        state->conn->smb1.client.capabilities,
        SMBnegprot,
        0, 0, &flags,
        0, 0, &flags2);

  return smb1cli_req_send(state, state->ev, state->conn,
        SMBnegprot,
        flags, ~flags,
        flags2, ~flags2,
        state->timeout_msec,
        0xFFFE, 0, NULL, /* pid, tid, session */
        0, NULL, /* wct, vwv */
        bytes.length, bytes.data);
}

static void smbXcli_negprot_smb1_done(struct tevent_req *subreq)
{
  struct tevent_req *req =
    tevent_req_callback_data(subreq,
    struct tevent_req);
  struct smbXcli_negprot_state *state =
    tevent_req_data(req,
    struct smbXcli_negprot_state);
  struct smbXcli_conn *conn = state->conn;
  struct iovec *recv_iov = NULL;
  uint8_t *inhdr = NULL;
  uint8_t wct;
  uint16_t *vwv;
  uint32_t num_bytes;
  uint8_t *bytes;
  NTSTATUS status;
  uint16_t protnum;
  size_t i;
  size_t num_prots = 0;
  uint8_t flags;
  uint32_t client_capabilities = conn->smb1.client.capabilities;
  uint32_t both_capabilities;
  uint32_t server_capabilities = 0;
  uint32_t capabilities;
  uint32_t client_max_xmit = conn->smb1.client.max_xmit;
  uint32_t server_max_xmit = 0;
  uint32_t max_xmit;
  uint32_t server_max_mux = 0;
  uint16_t server_security_mode = 0;
  uint32_t server_session_key = 0;
  bool server_readbraw = false;
  bool server_writebraw = false;
  bool server_lockread = false;
  bool server_writeunlock = false;
  struct GUID server_guid = GUID_zero();
  DATA_BLOB server_gss_blob = data_blob_null;
  uint8_t server_challenge[8] = {};
  char *server_workgroup = NULL;
  char *server_name = NULL;
  int server_time_zone = 0;
  NTTIME server_system_time = 0;
  static const struct smb1cli_req_expected_response expected[] = {
  {
    .status = NT_STATUS_OK,
    .wct = 0x11, /* NT1 */
  },
  {
    .status = NT_STATUS_OK,
    .wct = 0x0D, /* LM */
  },
  {
    .status = NT_STATUS_OK,
    .wct = 0x01, /* CORE */
  }
  };

  status = smb1cli_req_recv(subreq, state,
          &recv_iov,
          &inhdr,
          &wct,
          &vwv,
          NULL, /* pvwv_offset */
          &num_bytes,
          &bytes,
          NULL, /* pbytes_offset */
          NULL, /* pinbuf */
          expected, ARRAY_SIZE(expected));
  TALLOC_FREE(subreq);
  if (tevent_req_nterror(req, status)) {
    return;
  }
  if (inhdr == NULL) {
    tevent_req_nterror(req, NT_STATUS_INTERNAL_ERROR);
    return;
  }

  flags = CVAL(inhdr, HDR_FLG);

  protnum = SVAL(vwv, 0);

  for (i=0; i < ARRAY_SIZE(smb1cli_prots); i++) {
    if (smb1cli_prots[i].proto < state->conn->min_protocol) {
      continue;
    }

    if (smb1cli_prots[i].proto > state->conn->max_protocol) {
      continue;
    }

    if (protnum != num_prots) {
      num_prots++;
      continue;
    }

    conn->protocol = smb1cli_prots[i].proto;
    break;
  }

  if (conn->protocol == PROTOCOL_NONE) {
    DBG_ERR("No compatible protocol selected by server.\n");
    tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
    return;
  }

  if ((conn->protocol < PROTOCOL_NT1) && conn->mandatory_signing) {
    DEBUG(0,("smbXcli_negprot: SMB signing is mandatory "
       "and the selected protocol level doesn't support it.\n"));
    tevent_req_nterror(req, NT_STATUS_ACCESS_DENIED);
    return;
  }

  if (flags & FLAG_SUPPORT_LOCKREAD) {
    server_lockread = true;
    server_writeunlock = true;
  }

  if (conn->protocol >= PROTOCOL_NT1) {
    const char *client_signing = NULL;
    bool server_mandatory = false;
    bool server_allowed = false;
    const char *server_signing = NULL;
    bool ok;
    uint8_t key_len;

    if (wct != 0x11) {
      tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
      return;
    }

    /* NT protocol */
    server_security_mode = CVAL(vwv + 1, 0);
    server_max_mux = SVAL(vwv + 1, 1);
    server_max_xmit = IVAL(vwv + 3, 1);
    server_session_key = IVAL(vwv + 7, 1);
    server_time_zone = SVALS(vwv + 15, 1);
    server_time_zone *= 60;
    /* this time arrives in real GMT */
    server_system_time = BVAL(vwv + 11, 1);
    server_capabilities = IVAL(vwv + 9, 1);

    key_len = CVAL(vwv + 16, 1);

    if (server_capabilities & CAP_RAW_MODE) {
      server_readbraw = true;
      server_writebraw = true;
    }
    if (server_capabilities & CAP_LOCK_AND_READ) {
      server_lockread = true;
    }

    if (server_capabilities & CAP_EXTENDED_SECURITY) {
      DATA_BLOB blob1, blob2;

      if (num_bytes < 16) {
        tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
        return;
      }

      blob1 = data_blob_const(bytes, 16);
      status = GUID_from_data_blob(&blob1, &server_guid);
      if (tevent_req_nterror(req, status)) {
        return;
      }

      blob1 = data_blob_const(bytes+16, num_bytes-16);
      blob2 = data_blob_dup_talloc_s(state, blob1);
      if (blob1.length > 0 &&
          tevent_req_nomem(blob2.data, req)) {
        return;
      }
      server_gss_blob = blob2;
    } else {
      DATA_BLOB blob1, blob2;

      if (num_bytes < key_len) {
        tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
        return;
      }

      if (key_len != 0 && key_len != 8) {
        tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
        return;
      }

      if (key_len == 8) {
        memcpy(server_challenge, bytes, 8);
      }

      blob1 = data_blob_const(bytes+key_len, num_bytes-key_len);
      blob2 = data_blob_const(bytes+key_len, num_bytes-key_len);
      if (blob1.length > 0) {
        size_t len;

        len = utf16_null_terminated_len_n(blob1.data,
                  blob1.length);
        blob1.length = len;

        ok = convert_string_talloc(state,
                 CH_UTF16LE,
                 CH_UNIX,
                 blob1.data,
                 blob1.length,
                 &server_workgroup,
                 &len);
        if (!ok) {
          status = map_nt_error_from_unix_common(errno);
          tevent_req_nterror(req, status);
          return;
        }
      }

      blob2.data += blob1.length;
      blob2.length -= blob1.length;
      if (blob2.length > 0) {
        size_t len;

        ok = convert_string_talloc(state,
                 CH_UTF16LE,
                 CH_UNIX,
                 blob2.data,
                 blob2.length,
                 &server_name,
                 &len);
        if (!ok) {
          status = map_nt_error_from_unix_common(errno);
          tevent_req_nterror(req, status);
          return;
        }
      }
    }

    client_signing = "disabled";
    if (conn->allow_signing) {
      client_signing = "allowed";
    }
    if (conn->mandatory_signing) {
      client_signing = "required";
    }

    server_signing = "not supported";
    if (server_security_mode & NEGOTIATE_SECURITY_SIGNATURES_ENABLED) {
      server_signing = "supported";
      server_allowed = true;
    } else if (conn->mandatory_signing) {
      /*
       * We have mandatory signing as client
       * lets assume the server will look at our
       * FLAGS2_SMB_SECURITY_SIGNATURES_REQUIRED
       * flag in the session setup
       */
      server_signing = "not announced";
      server_allowed = true;
    }
    if (server_security_mode & NEGOTIATE_SECURITY_SIGNATURES_REQUIRED) {
      server_signing = "required";
      server_mandatory = true;
    }

    ok = smb1_signing_set_negotiated(conn->smb1.signing,
            server_allowed,
            server_mandatory);
    if (!ok) {
      DEBUG(1,("cli_negprot: SMB signing is required, "
         "but client[%s] and server[%s] mismatch\n",
         client_signing, server_signing));
      tevent_req_nterror(req, NT_STATUS_ACCESS_DENIED);
      return;
    }

  } else if (conn->protocol >= PROTOCOL_LANMAN1) {
    DATA_BLOB blob1;
    uint8_t key_len;
    time_t t;

    if (wct != 0x0D) {
      tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
      return;
    }

    server_security_mode = SVAL(vwv + 1, 0);
    server_max_xmit = SVAL(vwv + 2, 0);
    server_max_mux = SVAL(vwv + 3, 0);
    server_readbraw = ((SVAL(vwv + 5, 0) & 0x1) != 0);
    server_writebraw = ((SVAL(vwv + 5, 0) & 0x2) != 0);
    server_session_key = IVAL(vwv + 6, 0);
    server_time_zone = SVALS(vwv + 10, 0);
    server_time_zone *= 60;
    /* this time is converted to GMT by make_unix_date */
    t = pull_dos_date((const uint8_t *)(vwv + 8), server_time_zone);
    unix_to_nt_time(&server_system_time, t);
    key_len = SVAL(vwv + 11, 0);

    if (num_bytes < key_len) {
      tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
      return;
    }

    if (key_len != 0 && key_len != 8) {
      tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
      return;
    }

    if (key_len == 8) {
      memcpy(server_challenge, bytes, 8);
    }

    blob1 = data_blob_const(bytes+key_len, num_bytes-key_len);
    if (blob1.length > 0) {
      size_t len;
      bool ok;

      len = utf16_null_terminated_len_n(blob1.data,
                blob1.length);
      blob1.length = len;

      ok = convert_string_talloc(state,
               CH_DOS,
               CH_UNIX,
               blob1.data,
               blob1.length,
               &server_workgroup,
               &len);
      if (!ok) {
        status = map_nt_error_from_unix_common(errno);
        tevent_req_nterror(req, status);
        return;
      }
    }

  } else {
    /* the old core protocol */
    server_time_zone = get_time_zone(time(NULL));
    server_max_xmit = 1024;
    server_max_mux = 1;
  }

  if (server_max_xmit < 1024) {
    tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
    return;
  }

  if (server_max_mux < 1) {
    tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
    return;
  }

  /*
   * Now calculate the negotiated capabilities
   * based on the mask for:
   * - client only flags
   * - flags used in both directions
   * - server only flags
   */
  both_capabilities = client_capabilities & server_capabilities;
  capabilities = client_capabilities & SMB_CAP_CLIENT_MASK;
  capabilities |= both_capabilities & SMB_CAP_BOTH_MASK;
  capabilities |= server_capabilities & SMB_CAP_SERVER_MASK;

  max_xmit = MIN(client_max_xmit, server_max_xmit);

  conn->smb1.server.capabilities = server_capabilities;
  conn->smb1.capabilities = capabilities;

  conn->smb1.server.max_xmit = server_max_xmit;
  conn->smb1.max_xmit = max_xmit;

  conn->smb1.server.max_mux = server_max_mux;

  conn->smb1.server.security_mode = server_security_mode;

  conn->smb1.server.readbraw = server_readbraw;
  conn->smb1.server.writebraw = server_writebraw;
  conn->smb1.server.lockread = server_lockread;
  conn->smb1.server.writeunlock = server_writeunlock;

  conn->smb1.server.session_key = server_session_key;

  talloc_steal(conn, server_gss_blob.data);
  conn->smb1.server.gss_blob = server_gss_blob;
  conn->smb1.server.guid = server_guid;
  memcpy(conn->smb1.server.challenge, server_challenge, 8);
  conn->smb1.server.workgroup = talloc_move(conn, &server_workgroup);
  conn->smb1.server.name = talloc_move(conn, &server_name);

  conn->smb1.server.time_zone = server_time_zone;
  conn->smb1.server.system_time = server_system_time;

  tevent_req_done(req);
}

static size_t smbXcli_padding_helper(uint32_t offset, size_t n)
{
  if ((offset & (n-1)) == 0) return 0;
  return n - (offset & (n-1));
}

static struct tevent_req *smbXcli_negprot_smb2_subreq(struct smbXcli_negprot_state *state)
{
  struct smbXcli_conn *conn = state->conn;
  size_t i;
  uint8_t *buf;
  uint16_t dialect_count = 0;
  DATA_BLOB dyn = data_blob_null;

  for (i=0; i < ARRAY_SIZE(smb2cli_prots); i++) {
    bool ok;
    uint8_t val[2];

    if (smb2cli_prots[i].proto < conn->min_protocol) {
      continue;
    }

    if (smb2cli_prots[i].proto > conn->max_protocol) {
      continue;
    }

    SSVAL(val, 0, smb2cli_prots[i].smb2_dialect);

    ok = data_blob_append(state, &dyn, val, sizeof(val));
    if (!ok) {
      return NULL;
    }

    dialect_count++;
  }

  buf = state->smb2.fixed;
  SSVAL(buf, 0, 36);
  SSVAL(buf, 2, dialect_count);
  SSVAL(buf, 4, conn->smb2.client.security_mode);
  SSVAL(buf, 6, 0);  /* Reserved */
  if (conn->max_protocol >= PROTOCOL_SMB3_00) {
    SIVAL(buf, 8, conn->smb2.client.capabilities);
  } else {
    SIVAL(buf, 8, 0);  /* Capabilities */
  }
  if (conn->max_protocol >= PROTOCOL_SMB2_10) {
    struct GUID_ndr_buf guid_buf = { .buf = {0}, };

    GUID_to_ndr_buf(&conn->smb2.client.guid, &guid_buf);
    memcpy(buf+12, guid_buf.buf, 16); /* ClientGuid */
  } else {
    memset(buf+12, 0, 16);  /* ClientGuid */
  }

  if (conn->max_protocol >= PROTOCOL_SMB3_11) {
    const struct smb3_signing_capabilities *client_sign_algos =
      &conn->smb2.client.smb3_capabilities.signing;
    const struct smb3_encryption_capabilities *client_ciphers =
      &conn->smb2.client.smb3_capabilities.encryption;
    enum tls_verify_peer_state verify_peer;
    NTSTATUS status;
    struct smb2_negotiate_contexts c = { .num_contexts = 0, };
    uint8_t *netname_utf16 = NULL;
    size_t netname_utf16_len = 0;
    uint32_t offset;
    DATA_BLOB b;
    uint8_t p[38];
    static const uint8_t zeros[8] = {0, };
    size_t pad;
    bool ok;

    SSVAL(p, 0,  1); /* HashAlgorithmCount */
    SSVAL(p, 2, 32); /* SaltLength */
    SSVAL(p, 4, SMB2_PREAUTH_INTEGRITY_SHA512);
    generate_random_buffer(p + 6, 32);

    status = smb2_negotiate_context_add(
      state, &c, SMB2_PREAUTH_INTEGRITY_CAPABILITIES, p, 38);
    if (!NT_STATUS_IS_OK(status)) {
      return NULL;
    }

    if (client_ciphers->num_algos > 0) {
      size_t ofs = 0;
      SSVAL(p, ofs, client_ciphers->num_algos);
      ofs += 2;

      for (i = 0; i < client_ciphers->num_algos; i++) {
        size_t next_ofs = ofs + 2;
        SMB_ASSERT(next_ofs < ARRAY_SIZE(p));
        SSVAL(p, ofs, client_ciphers->algos[i]);
        ofs = next_ofs;
      }

      status = smb2_negotiate_context_add(
        state, &c, SMB2_ENCRYPTION_CAPABILITIES, p, ofs);
      if (!NT_STATUS_IS_OK(status)) {
        return NULL;
      }
    }

    if (client_sign_algos->num_algos > 0) {
      size_t ofs = 0;
      SSVAL(p, ofs, client_sign_algos->num_algos);
      ofs += 2;

      for (i = 0; i < client_sign_algos->num_algos; i++) {
        size_t next_ofs = ofs + 2;
        SMB_ASSERT(next_ofs < ARRAY_SIZE(p));
        SSVAL(p, ofs, client_sign_algos->algos[i]);
        ofs = next_ofs;
      }

      status = smb2_negotiate_context_add(
        state, &c, SMB2_SIGNING_CAPABILITIES, p, ofs);
      if (!NT_STATUS_IS_OK(status)) {
        return NULL;
      }
    }

    verify_peer = conn->transport->verify_peer;

    if (tstream_tls_verify_peer_trusted(verify_peer) &&
        !conn->smb2.client.smb3_capabilities
           .smb_encryption_over_quic)
    {
      uint8_t cap_buf[sizeof(uint32_t)];

      PUSH_LE_U32(cap_buf,
            0,
            SMB2_ACCEPT_TRANSPORT_LEVEL_SECURITY);

      status = smb2_negotiate_context_add(
        state,
        &c,
        SMB2_TRANSPORT_CAPABILITIES,
        cap_buf,
        sizeof(cap_buf));
      if (!NT_STATUS_IS_OK(status)) {
        return NULL;
      }
      conn->smb2.client
        .requested_transport_level_security = true;
    }

    ok = convert_string_talloc(state,
             CH_UNIX,
             CH_UTF16,
             conn->remote_name,
             strlen(conn->remote_name),
             &netname_utf16,
             &netname_utf16_len);
    if (!ok) {
      return NULL;
    }

    status = smb2_negotiate_context_add(state, &c,
          SMB2_NETNAME_NEGOTIATE_CONTEXT_ID,
          netname_utf16, netname_utf16_len);
    if (!NT_STATUS_IS_OK(status)) {
      return NULL;
    }

    if (state->in_ctx != NULL) {
      struct smb2_negotiate_contexts *ctxs = state->in_ctx;

      for (i=0; i<ctxs->num_contexts; i++) {
        struct smb2_negotiate_context *ctx =
          &ctxs->contexts[i];

        status = smb2_negotiate_context_add(
          state,
          &c,
          ctx->type,
          ctx->data.data,
          ctx->data.length);
        if (!NT_STATUS_IS_OK(status)) {
          return NULL;
        }
      }
    }

    status = smb2_negotiate_context_push(state, &b, c);
    if (!NT_STATUS_IS_OK(status)) {
      return NULL;
    }

    offset = SMB2_HDR_BODY + sizeof(state->smb2.fixed) + dyn.length;
    pad = smbXcli_padding_helper(offset, 8);

    ok = data_blob_append(state, &dyn, zeros, pad);
    if (!ok) {
      return NULL;
    }
    offset += pad;

    ok = data_blob_append(state, &dyn, b.data, b.length);
    if (!ok) {
      return NULL;
    }

    SIVAL(buf, 28, offset);   /* NegotiateContextOffset */
    SSVAL(buf, 32, c.num_contexts); /* NegotiateContextCount */
    SSVAL(buf, 34, 0);        /* Reserved */
  } else {
    SBVAL(buf, 28, 0); /* Reserved/ClientStartTime */
  }

  return smb2cli_req_send(state,
        state->ev,
        conn,
        SMB2_OP_NEGPROT,
        0, /* additional_flags */
        0, /* clear_flags */
        state->timeout_msec,
        NULL, /* tcon */
        NULL, /* session */
        state->smb2.fixed,
        sizeof(state->smb2.fixed),
        dyn.data,
        dyn.length,
        UINT16_MAX); /* max_dyn_len */
}

static NTSTATUS smbXcli_negprot_smb3_check_capabilities(struct tevent_req *req);

static void smbXcli_negprot_smb2_done(struct tevent_req *subreq)
{
  struct tevent_req *req =
    tevent_req_callback_data(subreq,
    struct tevent_req);
  struct smbXcli_negprot_state *state =
    tevent_req_data(req,
    struct smbXcli_negprot_state);
  struct smbXcli_conn *conn = state->conn;
  size_t security_offset, security_length;
  DATA_BLOB blob;
  NTSTATUS status;
  struct iovec *iov = NULL;
  uint8_t *body;
  size_t i;
  uint16_t dialect_revision;
  uint32_t negotiate_context_offset = 0;
  uint16_t negotiate_context_count = 0;
  DATA_BLOB negotiate_context_blob = data_blob_null;
  size_t avail;
  size_t ctx_ofs;
  size_t needed;
  struct smb2_negotiate_context *preauth = NULL;
  uint16_t hash_count;
  uint16_t salt_length;
  uint16_t hash_selected;
  gnutls_hash_hd_t hash_hnd = NULL;
  struct smb2_negotiate_context *sign_algo = NULL;
  struct smb2_negotiate_context *cipher = NULL;
  struct smb2_negotiate_context *posix = NULL;
  struct smb2_negotiate_context *transport_caps = NULL;
  struct iovec sent_iov[3] = {{0}, {0}, {0}};
  static const struct smb2cli_req_expected_response expected[] = {
  {
    .status = NT_STATUS_OK,
    .body_size = 0x41
  }
  };
  int rc;

  status = smb2cli_req_recv(subreq, state, &iov,
          expected, ARRAY_SIZE(expected));
  if (tevent_req_nterror(req, status)) {
    return;
  }
  if (iov == NULL) {
    tevent_req_nterror(req, NT_STATUS_INTERNAL_ERROR);
    return;
  }

  body = (uint8_t *)iov[1].iov_base;

  dialect_revision = SVAL(body, 4);

  for (i=0; i < ARRAY_SIZE(smb2cli_prots); i++) {
    if (smb2cli_prots[i].proto < state->conn->min_protocol) {
      continue;
    }

    if (smb2cli_prots[i].proto > state->conn->max_protocol) {
      continue;
    }

    if (smb2cli_prots[i].smb2_dialect != dialect_revision) {
      continue;
    }

    conn->protocol = smb2cli_prots[i].proto;
    break;
  }

  if (conn->protocol == PROTOCOL_NONE) {
    TALLOC_FREE(subreq);

    if (state->conn->min_protocol >= PROTOCOL_SMB2_02) {
      tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
      return;
    }

    if (dialect_revision != SMB2_DIALECT_REVISION_2FF) {
      tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
      return;
    }

    /* make sure we do not loop forever */
    state->conn->min_protocol = PROTOCOL_SMB2_02;

    /*
     * send a SMB2 negprot, in order to negotiate
     * the SMB2 dialect.
     */
    subreq = smbXcli_negprot_smb2_subreq(state);
    if (tevent_req_nomem(subreq, req)) {
      return;
    }
    tevent_req_set_callback(subreq, smbXcli_negprot_smb2_done, req);
    return;
  }

  conn->smb2.server.security_mode = SVAL(body, 2);
  if (conn->protocol >= PROTOCOL_SMB3_11) {
    negotiate_context_count = SVAL(body, 6);
  }

  blob = data_blob_const(body + 8, 16);
  status = GUID_from_data_blob(&blob, &conn->smb2.server.guid);
  if (tevent_req_nterror(req, status)) {
    return;
  }

  conn->smb2.server.capabilities  = IVAL(body, 24);
  conn->smb2.server.max_trans_size= IVAL(body, 28);
  conn->smb2.server.max_read_size = IVAL(body, 32);
  conn->smb2.server.max_write_size= IVAL(body, 36);
  conn->smb2.server.system_time = BVAL(body, 40);
  conn->smb2.server.start_time  = BVAL(body, 48);

  if (conn->smb2.server.max_trans_size == 0 ||
      conn->smb2.server.max_read_size == 0 ||
      conn->smb2.server.max_write_size == 0) {
    /*
     * We can't connect to servers we can't
     * do any operations on.
     */
    tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
    return;
  }

  security_offset = SVAL(body, 56);
  security_length = SVAL(body, 58);

  if (security_offset == 0) {
    /*
     * Azure sends security_offset = 0 and security_length = 0
     *
     * We just set security_offset to the expected value
     * in order to allow the further logic to work
     * as before.
     */
    if (security_length != 0) {
      tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
      return;
    }
    security_offset = SMB2_HDR_BODY + iov[1].iov_len;
  }

  if (security_offset != SMB2_HDR_BODY + iov[1].iov_len) {
    tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
    return;
  }

  if (security_length > iov[2].iov_len) {
    tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
    return;
  }

  conn->smb2.server.gss_blob = data_blob_talloc_s(conn,
              iov[2].iov_base,
              security_length);
  if (tevent_req_nomem(conn->smb2.server.gss_blob.data, req)) {
    return;
  }

  if (conn->protocol >= PROTOCOL_SMB3_00) {
    conn->smb2.server.sign_algo = SMB2_SIGNING_AES128_CMAC;
  } else {
    conn->smb2.server.sign_algo = SMB2_SIGNING_HMAC_SHA256;
  }

  if (conn->protocol < PROTOCOL_SMB3_11) {
    TALLOC_FREE(subreq);

    if (conn->smb2.server.capabilities & SMB2_CAP_ENCRYPTION) {
      conn->smb2.server.cipher = SMB2_ENCRYPTION_AES128_CCM;
    }

    status = smbXcli_negprot_smb3_check_capabilities(req);
    if (tevent_req_nterror(req, status)) {
      return;
    }

    tevent_req_done(req);
    return;
  }

  /*
   * Here we are now at SMB3_11, so encryption should be
   * negotiated via context, not capabilities.
   */

  if (conn->smb2.server.capabilities & SMB2_CAP_ENCRYPTION) {
    /*
     * Server set SMB2_CAP_ENCRYPTION capability,
     * but *SHOULD* not, not *MUST* not. Just mask it off.
     * NetApp seems to do this:
     * BUG: https://bugzilla.samba.org/show_bug.cgi?id=13009
     */
    conn->smb2.server.capabilities &= ~SMB2_CAP_ENCRYPTION;
  }

  negotiate_context_offset = IVAL(body, 60);
  if (negotiate_context_offset < security_offset) {
    tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
    return;
  }

  ctx_ofs = negotiate_context_offset - security_offset;
  if (ctx_ofs > iov[2].iov_len) {
    tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
    return;
  }
  avail = iov[2].iov_len - security_length;
  needed = iov[2].iov_len - ctx_ofs;
  if (needed > avail) {
    tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
    return;
  }

  negotiate_context_blob.data = (uint8_t *)iov[2].iov_base;
  negotiate_context_blob.length = iov[2].iov_len;

  negotiate_context_blob.data += ctx_ofs;
  negotiate_context_blob.length -= ctx_ofs;

  state->out_ctx = talloc_zero(state, struct smb2_negotiate_contexts);
  if (tevent_req_nomem(state->out_ctx, req)) {
    return;
  }

  status = smb2_negotiate_context_parse(state->out_ctx,
                negotiate_context_blob,
                negotiate_context_count,
                state->out_ctx);
  if (NT_STATUS_EQUAL(status, NT_STATUS_INVALID_PARAMETER)) {
    status = NT_STATUS_INVALID_NETWORK_RESPONSE;
  }
  if (tevent_req_nterror(req, status)) {
    return;
  }

  preauth = smb2_negotiate_context_find(
    state->out_ctx, SMB2_PREAUTH_INTEGRITY_CAPABILITIES);
  if (preauth == NULL) {
    tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
    return;
  }

  if (preauth->data.length < 6) {
    tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
    return;
  }

  hash_count = SVAL(preauth->data.data, 0);
  salt_length = SVAL(preauth->data.data, 2);
  hash_selected = SVAL(preauth->data.data, 4);

  if (hash_count != 1) {
    tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
    return;
  }

  if (preauth->data.length != (6 + salt_length)) {
    tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
    return;
  }

  if (hash_selected != SMB2_PREAUTH_INTEGRITY_SHA512) {
    tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
    return;
  }

  sign_algo = smb2_negotiate_context_find(
    state->out_ctx, SMB2_SIGNING_CAPABILITIES);
  if (sign_algo != NULL) {
    const struct smb3_signing_capabilities *client_sign_algos =
      &state->conn->smb2.client.smb3_capabilities.signing;
    bool found_selected = false;
    uint16_t sign_algo_count;
    uint16_t sign_algo_selected;

    if (client_sign_algos->num_algos == 0) {
      /*
       * We didn't ask for SMB2_ENCRYPTION_CAPABILITIES
       */
      tevent_req_nterror(req,
          NT_STATUS_INVALID_NETWORK_RESPONSE);
      return;
    }

    if (sign_algo->data.length < 2) {
      tevent_req_nterror(req,
          NT_STATUS_INVALID_NETWORK_RESPONSE);
      return;
    }

    sign_algo_count = SVAL(sign_algo->data.data, 0);
    if (sign_algo_count != 1) {
      tevent_req_nterror(req,
          NT_STATUS_INVALID_NETWORK_RESPONSE);
      return;
    }

    if (sign_algo->data.length < (2 + 2 * sign_algo_count)) {
      tevent_req_nterror(req,
          NT_STATUS_INVALID_NETWORK_RESPONSE);
      return;
    }
    sign_algo_selected = SVAL(sign_algo->data.data, 2);

    for (i = 0; i < client_sign_algos->num_algos; i++) {
      if (client_sign_algos->algos[i] == sign_algo_selected) {
        /*
         * We found a match
         */
        found_selected = true;
        break;
      }
    }

    if (!found_selected) {
      /*
       * The server send a sign_algo we didn't offer.
       */
      tevent_req_nterror(req,
          NT_STATUS_INVALID_NETWORK_RESPONSE);
      return;
    }

    conn->smb2.server.sign_algo = sign_algo_selected;
  }

  cipher = smb2_negotiate_context_find(
    state->out_ctx, SMB2_ENCRYPTION_CAPABILITIES);
  if (cipher != NULL) {
    const struct smb3_encryption_capabilities *client_ciphers =
      &state->conn->smb2.client.smb3_capabilities.encryption;
    bool found_selected = false;
    uint16_t cipher_count;
    uint16_t cipher_selected;

    if (client_ciphers->num_algos == 0) {
      /*
       * We didn't ask for SMB2_ENCRYPTION_CAPABILITIES
       */
      tevent_req_nterror(req,
          NT_STATUS_INVALID_NETWORK_RESPONSE);
      return;
    }

    if (cipher->data.length < 2) {
      tevent_req_nterror(req,
          NT_STATUS_INVALID_NETWORK_RESPONSE);
      return;
    }

    cipher_count = SVAL(cipher->data.data, 0);
    if (cipher_count != 1) {
      tevent_req_nterror(req,
          NT_STATUS_INVALID_NETWORK_RESPONSE);
      return;
    }

    if (cipher->data.length < (2 + 2 * cipher_count)) {
      tevent_req_nterror(req,
          NT_STATUS_INVALID_NETWORK_RESPONSE);
      return;
    }
    cipher_selected = SVAL(cipher->data.data, 2);

    for (i = 0; i < client_ciphers->num_algos; i++) {
      if (cipher_selected == SMB2_ENCRYPTION_NONE) {
        /*
         * encryption not supported
         */
        found_selected = true;
        break;
      }
      if (client_ciphers->algos[i] == cipher_selected) {
        /*
         * We found a match
         */
        found_selected = true;
        break;
      }
    }

    if (!found_selected) {
      /*
       * The server send a cipher we didn't offer.
       */
      tevent_req_nterror(req,
          NT_STATUS_INVALID_NETWORK_RESPONSE);
      return;
    }

    conn->smb2.server.cipher = cipher_selected;
  }

  if (conn->smb2.client.requested_transport_level_security) {
    transport_caps = smb2_negotiate_context_find(
      state->out_ctx, SMB2_TRANSPORT_CAPABILITIES);
  }
  if (transport_caps != NULL) {
    uint32_t caps;

    if (transport_caps->data.length != sizeof(uint32_t)) {
      tevent_req_nterror(req,
             NT_STATUS_INVALID_NETWORK_RESPONSE);
      return;
    }

    caps = PULL_LE_U32(transport_caps->data.data, 0);

    conn->smb2.server.transport_trusted =
      (caps & SMB2_ACCEPT_TRANSPORT_LEVEL_SECURITY) != 0;
  }

  posix = smb2_negotiate_context_find(
    state->out_ctx, SMB2_POSIX_EXTENSIONS_AVAILABLE);
  if (posix != NULL) {
    DATA_BLOB posix_blob = data_blob_const(
      SMB2_CREATE_TAG_POSIX, strlen(SMB2_CREATE_TAG_POSIX));
    int cmp = data_blob_cmp(&posix->data, &posix_blob);

    conn->smb2.server.smb311_posix = (cmp == 0);
  }


  /* First we hash the request */
  smb2cli_req_get_sent_iov(subreq, sent_iov);

  rc = gnutls_hash_init(&hash_hnd, GNUTLS_DIG_SHA512);
  if (rc < 0) {
    tevent_req_nterror(req,
           gnutls_error_to_ntstatus(rc, NT_STATUS_HASH_NOT_SUPPORTED));
    return;
  }

  rc = gnutls_hash(hash_hnd,
       conn->smb2.preauth_sha512,
       sizeof(conn->smb2.preauth_sha512));
  if (rc < 0) {
    gnutls_hash_deinit(hash_hnd, NULL);
    tevent_req_nterror(req,
           gnutls_error_to_ntstatus(rc, NT_STATUS_HASH_NOT_SUPPORTED));
    return;
  }
  for (i = 0; i < 3; i++) {
    rc = gnutls_hash(hash_hnd,
         sent_iov[i].iov_base,
         sent_iov[i].iov_len);
    if (rc < 0) {
      gnutls_hash_deinit(hash_hnd, NULL);
      tevent_req_nterror(req,
             gnutls_error_to_ntstatus(rc, NT_STATUS_HASH_NOT_SUPPORTED));
      return;
    }
  }

  /* This resets the hash state */
  gnutls_hash_output(hash_hnd, conn->smb2.preauth_sha512);
  TALLOC_FREE(subreq);

  /* And now we hash the response */
  rc = gnutls_hash(hash_hnd,
       conn->smb2.preauth_sha512,
       sizeof(conn->smb2.preauth_sha512));
  if (rc < 0) {
    gnutls_hash_deinit(hash_hnd, NULL);
    tevent_req_nterror(req,
           gnutls_error_to_ntstatus(rc, NT_STATUS_HASH_NOT_SUPPORTED));
    return;
  }
  for (i = 0; i < 3; i++) {
    rc = gnutls_hash(hash_hnd,
         iov[i].iov_base,
         iov[i].iov_len);
    if (rc < 0) {
      gnutls_hash_deinit(hash_hnd, NULL);
      tevent_req_nterror(req,
             gnutls_error_to_ntstatus(rc, NT_STATUS_HASH_NOT_SUPPORTED));
      return;
    }
  }
  gnutls_hash_deinit(hash_hnd, conn->smb2.preauth_sha512);
  if (rc < 0) {
    tevent_req_nterror(req,
           NT_STATUS_UNSUCCESSFUL);
    return;
  }

  status = smbXcli_negprot_smb3_check_capabilities(req);
  if (tevent_req_nterror(req, status)) {
    return;
  }

  tevent_req_done(req);
}

static NTSTATUS smbXcli_negprot_smb3_check_capabilities(struct tevent_req *req)
{
  struct smbXcli_negprot_state *state =
    tevent_req_data(req,
    struct smbXcli_negprot_state);
  struct smbXcli_conn *conn = state->conn;

  return smb311_capabilities_check(&conn->smb2.client.smb3_capabilities,
           "smbXcli_negprot",
           DBGLVL_ERR,
           NT_STATUS_ACCESS_DENIED,
           "client",
           conn->protocol,
           conn->smb2.server.sign_algo,
           conn->smb2.server.cipher);
}

static NTSTATUS smbXcli_negprot_dispatch_incoming(struct smbXcli_conn *conn,
              TALLOC_CTX *tmp_mem,
              uint8_t *inbuf)
{
  size_t num_pending = talloc_array_length(conn->pending);
  struct tevent_req *subreq;
  struct smbXcli_req_state *substate;
  struct tevent_req *req;
  uint32_t protocol_magic;
  size_t inbuf_len = smb_len_nbt(inbuf);

  if (num_pending != 1) {
    return NT_STATUS_INTERNAL_ERROR;
  }

  if (inbuf_len < 4) {
    return NT_STATUS_INVALID_NETWORK_RESPONSE;
  }

  subreq = conn->pending[0];
  substate = tevent_req_data(subreq, struct smbXcli_req_state);
  req = tevent_req_callback_data(subreq, struct tevent_req);

  protocol_magic = IVAL(inbuf, 4);

  switch (protocol_magic) {
  case SMB_MAGIC:
    tevent_req_set_callback(subreq, smbXcli_negprot_smb1_done, req);
    conn->dispatch_incoming = smb1cli_conn_dispatch_incoming;
    return smb1cli_conn_dispatch_incoming(conn, tmp_mem, inbuf);

  case SMB2_MAGIC:
    if (substate->smb2.recv_iov == NULL) {
      /*
       * For the SMB1 negprot we have move it.
       */
      substate->smb2.recv_iov = substate->smb1.recv_iov;
      substate->smb1.recv_iov = NULL;
    }

    /*
     * we got an SMB2 answer, which consumed sequence number 0
     * so we need to use 1 as the next one.
     *
     * we also need to set the current credits to 0
     * as we consumed the initial one. The SMB2 answer
     * hopefully grant us a new credit.
     */
    conn->smb2.mid = 1;
    conn->smb2.cur_credits = 0;
    tevent_req_set_callback(subreq, smbXcli_negprot_smb2_done, req);
    conn->dispatch_incoming = smb2cli_conn_dispatch_incoming;
    return smb2cli_conn_dispatch_incoming(conn, tmp_mem, inbuf);
  }

  DEBUG(10, ("Got non-SMB PDU\n"));
  return NT_STATUS_INVALID_NETWORK_RESPONSE;
}

NTSTATUS smbXcli_negprot_recv(
  struct tevent_req *req,
  TALLOC_CTX *mem_ctx,
  struct smb2_negotiate_contexts **out_ctx)
{
  struct smbXcli_negprot_state *state = tevent_req_data(
    req, struct smbXcli_negprot_state);
  NTSTATUS status;

  if (tevent_req_is_nterror(req, &status)) {
    tevent_req_received(req);
    return status;
  }

  if (out_ctx != NULL) {
    *out_ctx = talloc_move(mem_ctx, &state->out_ctx);
  }

  tevent_req_received(req);
  return NT_STATUS_OK;
}

NTSTATUS smbXcli_negprot(struct smbXcli_conn *conn,
       uint32_t timeout_msec,
       enum protocol_types min_protocol,
       enum protocol_types max_protocol,
       struct smb2_negotiate_contexts *in_ctx,
       TALLOC_CTX *mem_ctx,
       struct smb2_negotiate_contexts **out_ctx)
{
  TALLOC_CTX *frame = talloc_stackframe();
  struct tevent_context *ev;
  struct tevent_req *req;
  NTSTATUS status = NT_STATUS_NO_MEMORY;
  bool ok;

  if (smbXcli_conn_has_async_calls(conn)) {
    /*
     * Can't use sync call while an async call is in flight
     */
    status = NT_STATUS_INVALID_PARAMETER_MIX;
    goto fail;
  }
  ev = samba_tevent_context_init(frame);
  if (ev == NULL) {
    goto fail;
  }
  req = smbXcli_negprot_send(
    frame,
    ev,
    conn,
    timeout_msec,
    min_protocol,
    max_protocol,
    WINDOWS_CLIENT_PURE_SMB2_NEGPROT_INITIAL_CREDIT_ASK,
    in_ctx);
  if (req == NULL) {
    goto fail;
  }
  ok = tevent_req_poll_ntstatus(req, ev, &status);
  if (!ok) {
    goto fail;
  }
  status = smbXcli_negprot_recv(req, mem_ctx, out_ctx);
 fail:
  TALLOC_FREE(frame);
  return status;
}

struct smb2cli_validate_negotiate_info_state {
  struct smbXcli_conn *conn;
  DATA_BLOB in_input_buffer;
  DATA_BLOB in_output_buffer;
  DATA_BLOB out_input_buffer;
  DATA_BLOB out_output_buffer;
  uint16_t dialect;
};

static void smb2cli_validate_negotiate_info_done(struct tevent_req *subreq);

struct tevent_req *smb2cli_validate_negotiate_info_send(TALLOC_CTX *mem_ctx,
            struct tevent_context *ev,
            struct smbXcli_conn *conn,
            uint32_t timeout_msec,
            struct smbXcli_session *session,
            struct smbXcli_tcon *tcon)
{
  struct tevent_req *req;
  struct smb2cli_validate_negotiate_info_state *state;
  uint8_t *buf;
  uint16_t dialect_count = 0;
  struct tevent_req *subreq;
  bool _save_should_sign;
  size_t i;

  req = tevent_req_create(mem_ctx, &state,
        struct smb2cli_validate_negotiate_info_state);
  if (req == NULL) {
    return NULL;
  }
  state->conn = conn;

  state->in_input_buffer = data_blob_talloc_zero(state,
          4 + 16 + 1 + 1 + 2);
  if (tevent_req_nomem(state->in_input_buffer.data, req)) {
    return tevent_req_post(req, ev);
  }
  buf = state->in_input_buffer.data;

  if (state->conn->max_protocol >= PROTOCOL_SMB3_00) {
    SIVAL(buf, 0, conn->smb2.client.capabilities);
  } else {
    SIVAL(buf, 0, 0); /* Capabilities */
  }
  if (state->conn->max_protocol >= PROTOCOL_SMB2_10) {
    struct GUID_ndr_buf guid_buf = { .buf = {0}, };

    GUID_to_ndr_buf(&conn->smb2.client.guid, &guid_buf);
    memcpy(buf+4, guid_buf.buf, 16); /* ClientGuid */
  } else {
    memset(buf+4, 0, 16); /* ClientGuid */
  }
  if (state->conn->min_protocol >= PROTOCOL_SMB2_02) {
    SCVAL(buf, 20, conn->smb2.client.security_mode);
  } else {
    SCVAL(buf, 20, 0);
  }
  SCVAL(buf, 21, 0); /* reserved */

  for (i=0; i < ARRAY_SIZE(smb2cli_prots); i++) {
    bool ok;
    size_t ofs;

    if (smb2cli_prots[i].proto < state->conn->min_protocol) {
      continue;
    }

    if (smb2cli_prots[i].proto > state->conn->max_protocol) {
      continue;
    }

    if (smb2cli_prots[i].proto == state->conn->protocol) {
      state->dialect = smb2cli_prots[i].smb2_dialect;
    }

    ofs = state->in_input_buffer.length;
    ok = data_blob_realloc(state, &state->in_input_buffer,
               ofs + 2);
    if (!ok) {
      tevent_req_oom(req);
      return tevent_req_post(req, ev);
    }

    buf = state->in_input_buffer.data;
    SSVAL(buf, ofs, smb2cli_prots[i].smb2_dialect);

    dialect_count++;
  }
  buf = state->in_input_buffer.data;
  SSVAL(buf, 22, dialect_count);

  _save_should_sign = smb2cli_tcon_is_signing_on(tcon);
  smb2cli_tcon_should_sign(tcon, true);
  subreq = smb2cli_ioctl_send(state, ev, conn,
            timeout_msec, session, tcon,
            UINT64_MAX, /* in_fid_persistent */
            UINT64_MAX, /* in_fid_volatile */
            FSCTL_VALIDATE_NEGOTIATE_INFO,
            0, /* in_max_input_length */
            &state->in_input_buffer,
            24, /* in_max_output_length */
            &state->in_output_buffer,
            SMB2_IOCTL_FLAG_IS_FSCTL);
  smb2cli_tcon_should_sign(tcon, _save_should_sign);
  if (tevent_req_nomem(subreq, req)) {
    return tevent_req_post(req, ev);
  }
  tevent_req_set_callback(subreq,
        smb2cli_validate_negotiate_info_done,
        req);

  return req;
}

static void smb2cli_validate_negotiate_info_done(struct tevent_req *subreq)
{
  struct tevent_req *req =
    tevent_req_callback_data(subreq,
    struct tevent_req);
  struct smb2cli_validate_negotiate_info_state *state =
    tevent_req_data(req,
    struct smb2cli_validate_negotiate_info_state);
  NTSTATUS status;
  const uint8_t *buf;
  uint32_t capabilities;
  DATA_BLOB guid_blob;
  struct GUID server_guid;
  uint16_t security_mode;
  uint16_t dialect;

  status = smb2cli_ioctl_recv(subreq, state,
            &state->out_input_buffer,
            &state->out_output_buffer);
  TALLOC_FREE(subreq);

  /*
   * This response must be signed correctly for
   * these "normal" error codes to be processed.
   * If the packet wasn't signed correctly we will get
   * NT_STATUS_ACCESS_DENIED or NT_STATUS_HMAC_NOT_SUPPORTED,
   * or NT_STATUS_INVALID_NETWORK_RESPONSE
   * from smb2_signing_check_pdu().
   *
   * We must never ignore the above errors here.
   */

  if (NT_STATUS_EQUAL(status, NT_STATUS_FILE_CLOSED)) {
    /*
     * The response was signed, but not supported
     *
     * Older Windows and Samba releases return
     * NT_STATUS_FILE_CLOSED.
     */
    tevent_req_done(req);
    return;
  }
  if (NT_STATUS_EQUAL(status, NT_STATUS_INVALID_DEVICE_REQUEST)) {
    /*
     * The response was signed, but not supported
     *
     * This is returned by the NTVFS based Samba 4.x file server
     * for file shares.
     */
    tevent_req_done(req);
    return;
  }
  if (NT_STATUS_EQUAL(status, NT_STATUS_FS_DRIVER_REQUIRED)) {
    /*
     * The response was signed, but not supported
     *
     * This is returned by the NTVFS based Samba 4.x file server
     * for ipc shares.
     */
    tevent_req_done(req);
    return;
  }
  if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_SUPPORTED)) {
    /*
     * The response was signed, but not supported
     *
     * This might be returned by older Windows versions or by
     * NetApp SMB server implementations.
     *
     * See
     *
     * https://blogs.msdn.microsoft.com/openspecification/2012/06/28/smb3-secure-dialect-negotiation/
     *
     */
    tevent_req_done(req);
    return;
  }
  if (NT_STATUS_EQUAL(status, NT_STATUS_INVALID_PARAMETER)) {
    /*
     * The response was signed, but not supported
     *
     * This might be returned by NetApp Ontap 7.3.7 SMB server
     * implementations.
     *
     * BUG: https://bugzilla.samba.org/show_bug.cgi?id=14607
     *
     */
    tevent_req_done(req);
    return;
  }
  if (tevent_req_nterror(req, status)) {
    return;
  }

  if (state->out_output_buffer.length != 24) {
    tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
    return;
  }

  buf = state->out_output_buffer.data;

  capabilities = IVAL(buf, 0);
  guid_blob = data_blob_const(buf + 4, 16);
  status = GUID_from_data_blob(&guid_blob, &server_guid);
  if (tevent_req_nterror(req, status)) {
    return;
  }
  security_mode = CVAL(buf, 20);
  dialect = SVAL(buf, 22);

  if (capabilities != state->conn->smb2.server.capabilities) {
    tevent_req_nterror(req, NT_STATUS_ACCESS_DENIED);
    return;
  }

  if (!GUID_equal(&server_guid, &state->conn->smb2.server.guid)) {
    tevent_req_nterror(req, NT_STATUS_ACCESS_DENIED);
    return;
  }

  if (security_mode != state->conn->smb2.server.security_mode) {
    tevent_req_nterror(req, NT_STATUS_ACCESS_DENIED);
    return;
  }

  if (dialect != state->dialect) {
    tevent_req_nterror(req, NT_STATUS_ACCESS_DENIED);
    return;
  }

  tevent_req_done(req);
}

NTSTATUS smb2cli_validate_negotiate_info_recv(struct tevent_req *req)
{
  return tevent_req_simple_recv_ntstatus(req);
}

static int smbXcli_session_destructor(struct smbXcli_session *session)
{
  if (session->conn == NULL) {
    return 0;
  }

  DLIST_REMOVE(session->conn->sessions, session);
  return 0;
}

struct smbXcli_session *smbXcli_session_create(TALLOC_CTX *mem_ctx,
                 struct smbXcli_conn *conn)
{
  struct smbXcli_session *session;
  NTSTATUS status;

  session = talloc_zero(mem_ctx, struct smbXcli_session);
  if (session == NULL) {
    return NULL;
  }
  session->smb2 = talloc_zero(session, struct smb2cli_session);
  if (session->smb2 == NULL) {
    talloc_free(session);
    return NULL;
  }
  talloc_set_destructor(session, smbXcli_session_destructor);

  status = smb2_signing_key_sign_create(session->smb2,
                conn->smb2.server.sign_algo,
                NULL, /* no master key */
                NULL, /* derivations */
                &session->smb2->signing_key);
  if (!NT_STATUS_IS_OK(status)) {
    talloc_free(session);
    return NULL;
  }

  DLIST_ADD_END(conn->sessions, session);
  session->conn = conn;

  status = smb2_signing_key_sign_create(session,
                conn->smb2.server.sign_algo,
                NULL, /* no master key */
                NULL, /* derivations */
                &session->smb2_channel.signing_key);
  if (!NT_STATUS_IS_OK(status)) {
    talloc_free(session);
    return NULL;
  }

  memcpy(session->smb2_channel.preauth_sha512,
         conn->smb2.preauth_sha512,
         sizeof(session->smb2_channel.preauth_sha512));

  return session;
}

struct smbXcli_session *smbXcli_session_shallow_copy(TALLOC_CTX *mem_ctx,
            struct smbXcli_session *src)
{
  struct smbXcli_session *session;
  struct timespec ts;
  NTTIME nt;

  session = talloc_zero(mem_ctx, struct smbXcli_session);
  if (session == NULL) {
    return NULL;
  }
  session->smb2 = talloc_zero(session, struct smb2cli_session);
  if (session->smb2 == NULL) {
    talloc_free(session);
    return NULL;
  }

  /*
   * Note we keep a pointer to the session keys of the
   * main session and rely on the caller to free the
   * shallow copy first!
   */
  session->conn = src->conn;
  *session->smb2 = *src->smb2;
  session->smb2_channel = src->smb2_channel;
  session->disconnect_expired = src->disconnect_expired;

  /*
   * This is only supposed to be called in test code
   * but we should not reuse nonces!
   *
   * Add the current timestamp as NTTIME to nonce_high
   * and set nonce_low to a value we can recognize in captures.
   */
  clock_gettime_mono(&ts);
  nt = unix_timespec_to_nt_time(ts);
  nt &= session->smb2->nonce_high_max;
  if (nt == session->smb2->nonce_high_max || nt < UINT8_MAX) {
    talloc_free(session);
    return NULL;
  }
  session->smb2->nonce_high += nt;
  session->smb2->nonce_low = UINT32_MAX;

  DLIST_ADD_END(src->conn->sessions, session);
  talloc_set_destructor(session, smbXcli_session_destructor);

  return session;
}

bool smbXcli_session_is_guest(struct smbXcli_session *session)
{
  if (session == NULL) {
    return false;
  }

  if (session->conn == NULL) {
    return false;
  }

  if (session->conn->mandatory_signing) {
    return false;
  }

  if (session->conn->protocol >= PROTOCOL_SMB2_02) {
    if (session->smb2->session_flags & SMB2_SESSION_FLAG_IS_GUEST) {
      return true;
    }
    return false;
  }

  if (session->smb1.action & SMB_SETUP_GUEST) {
    return true;
  }

  return false;
}

bool smbXcli_session_is_authenticated(struct smbXcli_session *session)
{
  const DATA_BLOB *application_key;

  if (session == NULL) {
    return false;
  }

  if (session->conn == NULL) {
    return false;
  }

  /*
   * If we have an application key we had a session key negotiated
   * at auth time.
   */
  if (session->conn->protocol >= PROTOCOL_SMB2_02) {
    if (!smb2_signing_key_valid(session->smb2->application_key)) {
      return false;
    }
    application_key = &session->smb2->application_key->blob;
  } else {
    application_key = &session->smb1.application_key;
  }

  if (application_key->length == 0) {
    return false;
  }

  return true;
}

NTSTATUS smb2cli_session_signing_key(struct smbXcli_session *session,
             TALLOC_CTX *mem_ctx,
             DATA_BLOB *key)
{
  const struct smb2_signing_key *sig = NULL;

  if (session->conn == NULL) {
    return NT_STATUS_NO_USER_SESSION_KEY;
  }

  /*
   * Use channel signing key if there is one, otherwise fallback
   * to session.
   */

  if (smb2_signing_key_valid(session->smb2_channel.signing_key)) {
    sig = session->smb2_channel.signing_key;
  } else if (smb2_signing_key_valid(session->smb2->signing_key)) {
    sig = session->smb2->signing_key;
  } else {
    return NT_STATUS_NO_USER_SESSION_KEY;
  }

  *key = data_blob_dup_talloc_s(mem_ctx, sig->blob);
  if (key->data == NULL) {
    return NT_STATUS_NO_MEMORY;
  }

  return NT_STATUS_OK;
}

NTSTATUS smb2cli_session_encryption_key(struct smbXcli_session *session,
          TALLOC_CTX *mem_ctx,
          DATA_BLOB *key)
{
  if (session->conn == NULL) {
    return NT_STATUS_NO_USER_SESSION_KEY;
  }

  if (session->conn->protocol < PROTOCOL_SMB3_00) {
    return NT_STATUS_NO_USER_SESSION_KEY;
  }

  if (!smb2_signing_key_valid(session->smb2->encryption_key)) {
    return NT_STATUS_NO_USER_SESSION_KEY;
  }

  *key = data_blob_dup_talloc_s(mem_ctx,
              session->smb2->encryption_key->blob);
  if (key->data == NULL) {
    return NT_STATUS_NO_MEMORY;
  }

  return NT_STATUS_OK;
}

NTSTATUS smb2cli_session_decryption_key(struct smbXcli_session *session,
          TALLOC_CTX *mem_ctx,
          DATA_BLOB *key)
{
  if (session->conn == NULL) {
    return NT_STATUS_NO_USER_SESSION_KEY;
  }

  if (session->conn->protocol < PROTOCOL_SMB3_00) {
    return NT_STATUS_NO_USER_SESSION_KEY;
  }

  if (!smb2_signing_key_valid(session->smb2->decryption_key)) {
    return NT_STATUS_NO_USER_SESSION_KEY;
  }

  *key = data_blob_dup_talloc_s(mem_ctx,
              session->smb2->decryption_key->blob);
  if (key->data == NULL) {
    return NT_STATUS_NO_MEMORY;
  }

  return NT_STATUS_OK;
}

NTSTATUS smbXcli_session_application_key(struct smbXcli_session *session,
           TALLOC_CTX *mem_ctx,
           DATA_BLOB *key)
{
  const DATA_BLOB *application_key;

  *key = data_blob_null;

  if (session->conn == NULL) {
    return NT_STATUS_NO_USER_SESSION_KEY;
  }

  if (session->conn->protocol >= PROTOCOL_SMB2_02) {
    if (!smb2_signing_key_valid(session->smb2->application_key)) {
      return NT_STATUS_NO_USER_SESSION_KEY;
    }
    application_key = &session->smb2->application_key->blob;
  } else {
    application_key = &session->smb1.application_key;
  }

  if (application_key->length == 0) {
    return NT_STATUS_NO_USER_SESSION_KEY;
  }

  *key = data_blob_dup_talloc_s(mem_ctx, *application_key);
  if (key->data == NULL) {
    return NT_STATUS_NO_MEMORY;
  }

  return NT_STATUS_OK;
}

void smbXcli_session_set_disconnect_expired(struct smbXcli_session *session)
{
  session->disconnect_expired = true;
}

uint16_t smb1cli_session_current_id(struct smbXcli_session *session)
{
  return session->smb1.session_id;
}

void smb1cli_session_set_id(struct smbXcli_session *session,
          uint16_t session_id)
{
  session->smb1.session_id = session_id;
}

void smb1cli_session_set_action(struct smbXcli_session *session,
        uint16_t action)
{
  session->smb1.action = action;
}

NTSTATUS smb1cli_session_set_session_key(struct smbXcli_session *session,
           const DATA_BLOB _session_key)
{
  struct smbXcli_conn *conn = session->conn;
  uint8_t session_key[16];

  if (conn == NULL) {
    return NT_STATUS_INVALID_PARAMETER_MIX;
  }

  if (session->smb1.application_key.length != 0) {
    /*
     * TODO: do not allow this...
     *
     * return NT_STATUS_INVALID_PARAMETER_MIX;
     */
    data_blob_clear_free(&session->smb1.application_key);
    session->smb1.protected_key = false;
  }

  if (_session_key.length == 0) {
    return NT_STATUS_OK;
  }

  ZERO_STRUCT(session_key);
  memcpy(session_key, _session_key.data,
         MIN(_session_key.length, sizeof(session_key)));

  session->smb1.application_key = data_blob_talloc_s(
    session, session_key, sizeof(session_key));
  ZERO_STRUCT(session_key);
  if (session->smb1.application_key.data == NULL) {
    return NT_STATUS_NO_MEMORY;
  }

  session->smb1.protected_key = false;

  return NT_STATUS_OK;
}

NTSTATUS smb1cli_session_protect_session_key(struct smbXcli_session *session)
{
  NTSTATUS status;

  if (session->smb1.protected_key) {
    /* already protected */
    return NT_STATUS_OK;
  }

  if (session->smb1.application_key.length != 16) {
    return NT_STATUS_INVALID_PARAMETER_MIX;
  }

  status = smb1_key_derivation(session->smb1.application_key.data,
            session->smb1.application_key.length,
            session->smb1.application_key.data);
  if (!NT_STATUS_IS_OK(status)) {
    return status;
  }

  session->smb1.protected_key = true;

  return NT_STATUS_OK;
}

uint8_t smb2cli_session_security_mode(struct smbXcli_session *session)
{
  struct smbXcli_conn *conn = session->conn;
  uint8_t security_mode = 0;

  if (conn == NULL) {
    return security_mode;
  }

  security_mode = SMB2_NEGOTIATE_SIGNING_ENABLED;
  if (conn->mandatory_signing) {
    security_mode |= SMB2_NEGOTIATE_SIGNING_REQUIRED;
  }
  if (session->smb2->should_sign) {
    security_mode |= SMB2_NEGOTIATE_SIGNING_REQUIRED;
  }

  return security_mode;
}

uint64_t smb2cli_session_current_id(struct smbXcli_session *session)
{
  return session->smb2->session_id;
}

uint16_t smb2cli_session_get_flags(struct smbXcli_session *session)
{
  return session->smb2->session_flags;
}

void smb2cli_session_set_id_and_flags(struct smbXcli_session *session,
              uint64_t session_id,
              uint16_t session_flags)
{
  session->smb2->session_id = session_id;
  session->smb2->session_flags = session_flags;
}

void smb2cli_session_increment_channel_sequence(struct smbXcli_session *session)
{
  session->smb2->channel_sequence += 1;
}

uint16_t smb2cli_session_reset_channel_sequence(struct smbXcli_session *session,
            uint16_t channel_sequence)
{
  uint16_t prev_cs;

  prev_cs = session->smb2->channel_sequence;
  session->smb2->channel_sequence = channel_sequence;

  return prev_cs;
}

uint16_t smb2cli_session_current_channel_sequence(struct smbXcli_session *session)
{
  return session->smb2->channel_sequence;
}

void smb2cli_session_start_replay(struct smbXcli_session *session)
{
  session->smb2->replay_active = true;
}

void smb2cli_session_stop_replay(struct smbXcli_session *session)
{
  session->smb2->replay_active = false;
}

void smb2cli_session_require_signed_response(struct smbXcli_session *session,
               bool require_signed_response)
{
  session->smb2->require_signed_response = require_signed_response;
}

void smb2cli_session_torture_anonymous_signing(struct smbXcli_session *session,
                 bool anonymous_signing)
{
  session->smb2->anonymous_signing = anonymous_signing;
}

void smb2cli_session_torture_anonymous_encryption(struct smbXcli_session *session,
              bool anonymous_encryption)
{
  session->smb2->anonymous_encryption = anonymous_encryption;
}

void smb2cli_session_torture_no_signing_disconnect(struct smbXcli_session *session)
{
  session->smb2->no_signing_disconnect = true;
}

NTSTATUS smb2cli_session_update_preauth(struct smbXcli_session *session,
          const struct iovec *iov)
{
  gnutls_hash_hd_t hash_hnd = NULL;
  size_t i;
  int rc;

  if (session->conn == NULL) {
    return NT_STATUS_INTERNAL_ERROR;
  }

  if (session->conn->protocol < PROTOCOL_SMB3_11) {
    return NT_STATUS_OK;
  }

  if (smb2_signing_key_valid(session->smb2_channel.signing_key)) {
    return NT_STATUS_OK;
  }

  rc = gnutls_hash_init(&hash_hnd,
            GNUTLS_DIG_SHA512);
  if (rc < 0) {
    return gnutls_error_to_ntstatus(rc, NT_STATUS_HASH_NOT_SUPPORTED);
  }

  rc = gnutls_hash(hash_hnd,
       session->smb2_channel.preauth_sha512,
       sizeof(session->smb2_channel.preauth_sha512));
  if (rc < 0) {
    gnutls_hash_deinit(hash_hnd, NULL);
    return gnutls_error_to_ntstatus(rc, NT_STATUS_HASH_NOT_SUPPORTED);
  }
  for (i = 0; i < 3; i++) {
    rc = gnutls_hash(hash_hnd,
         iov[i].iov_base,
         iov[i].iov_len);
    if (rc < 0) {
      gnutls_hash_deinit(hash_hnd, NULL);
      return gnutls_error_to_ntstatus(rc, NT_STATUS_HASH_NOT_SUPPORTED);
    }
  }
  gnutls_hash_deinit(hash_hnd, session->smb2_channel.preauth_sha512);

  return NT_STATUS_OK;
}

NTSTATUS smb2cli_session_set_session_key(struct smbXcli_session *session,
           const DATA_BLOB _session_key,
           const struct iovec *recv_iov)
{
  struct smbXcli_conn *conn = session->conn;
  uint16_t no_sign_flags = 0;
  bool check_signature = true;
  uint32_t hdr_flags;
  NTSTATUS status;
  struct smb2_signing_derivations derivations = {
    .signing = NULL,
  };
  DATA_BLOB preauth_hash = data_blob_null;
  size_t nonce_size = 0;

  if (conn == NULL) {
    return NT_STATUS_INVALID_PARAMETER_MIX;
  }

  if (recv_iov[0].iov_len != SMB2_HDR_BODY) {
    return NT_STATUS_INVALID_PARAMETER_MIX;
  }

  if (!conn->mandatory_signing) {
    /*
     * only allow guest sessions without
     * mandatory signing.
     *
     * If we try an authentication with username != ""
     * and the server let us in without verifying the
     * password we don't have a negotiated session key
     * for signing.
     */
    no_sign_flags = SMB2_SESSION_FLAG_IS_GUEST;
  }

  if (session->smb2->session_flags & no_sign_flags) {
    session->smb2->should_sign = false;
    return NT_STATUS_OK;
  }

  if (smb2_signing_key_valid(session->smb2->signing_key)) {
    return NT_STATUS_INVALID_PARAMETER_MIX;
  }

  if (conn->protocol >= PROTOCOL_SMB3_11) {
    preauth_hash = data_blob_const(session->smb2_channel.preauth_sha512,
        sizeof(session->smb2_channel.preauth_sha512));
  }

  smb2_signing_derivations_fill_const_stack(&derivations,
              conn->protocol,
              preauth_hash);

  if (session->smb2->anonymous_encryption) {
    goto skip_signing_key;
  }

  status = smb2_signing_key_sign_create(session->smb2,
                conn->smb2.server.sign_algo,
                &_session_key,
                derivations.signing,
                &session->smb2->signing_key);
  if (!NT_STATUS_IS_OK(status)) {
    return status;
  }

  if (session->smb2->anonymous_signing) {
    /*
     * skip encryption and application keys
     */
    goto skip_application_key;
  }

skip_signing_key:

  status = smb2_signing_key_cipher_create(session->smb2,
            conn->smb2.server.cipher,
            &_session_key,
            derivations.cipher_c2s,
            &session->smb2->encryption_key);
  if (!NT_STATUS_IS_OK(status)) {
    return status;
  }

  status = smb2_signing_key_cipher_create(session->smb2,
            conn->smb2.server.cipher,
            &_session_key,
            derivations.cipher_s2c,
            &session->smb2->decryption_key);
  if (!NT_STATUS_IS_OK(status)) {
    return status;
  }

  if (session->smb2->anonymous_encryption) {
    goto skip_application_key;
  }

  status = smb2_signing_key_sign_create(session->smb2,
                conn->smb2.server.sign_algo,
                &_session_key,
                derivations.application,
                &session->smb2->application_key);
  if (!NT_STATUS_IS_OK(status)) {
    return status;
  }

skip_application_key:

  status = smb2_signing_key_copy(session,
               session->smb2->signing_key,
               &session->smb2_channel.signing_key);
  if (!NT_STATUS_IS_OK(status)) {
    return status;
  }

  check_signature = conn->mandatory_signing;

  if (conn->protocol >= PROTOCOL_SMB3_11) {
    check_signature = true;
  }

  if (session->smb2->anonymous_signing) {
    check_signature = false;
  }

  if (session->smb2->anonymous_encryption) {
    check_signature = false;
  }

  hdr_flags = IVAL(recv_iov[0].iov_base, SMB2_HDR_FLAGS);
  if (hdr_flags & SMB2_HDR_FLAG_SIGNED) {
    /*
     * Sadly some vendors don't sign the
     * final SMB2 session setup response
     *
     * At least Windows and Samba are always doing this
     * if there's a session key available.
     *
     * We only check the signature if it's mandatory
     * or SMB2_HDR_FLAG_SIGNED is provided.
     */
    check_signature = true;
  }

  if (check_signature) {
    status = smb2_signing_check_pdu(session->smb2_channel.signing_key,
            recv_iov, 3);
    if (!NT_STATUS_IS_OK(status)) {
      return status;
    }
  }

  session->smb2->should_sign = false;
  session->smb2->should_encrypt = false;

  if (conn->desire_signing) {
    session->smb2->should_sign = true;
  }

  if (conn->smb2.server.security_mode & SMB2_NEGOTIATE_SIGNING_REQUIRED) {
    session->smb2->should_sign = true;
  }

  if (session->smb2->session_flags & SMB2_SESSION_FLAG_ENCRYPT_DATA) {
    session->smb2->should_encrypt = true;
  }

  if (conn->protocol < PROTOCOL_SMB3_00) {
    session->smb2->should_encrypt = false;
  }

  if (conn->smb2.server.cipher == 0) {
    session->smb2->should_encrypt = false;
  }

  if (session->smb2->anonymous_signing) {
    session->smb2->should_sign = true;
  }

  if (session->smb2->anonymous_encryption) {
    session->smb2->should_encrypt = true;
    session->smb2->should_sign = false;
  }

  /*
   * CCM and GCM algorithms must never have their
   * nonce wrap, or the security of the whole
   * communication and the keys is destroyed.
   * We must drop the connection once we have
   * transferred too much data.
   *
   * NOTE: We assume nonces greater than 8 bytes.
   */
  generate_nonce_buffer((uint8_t *)&session->smb2->nonce_high_random,
            sizeof(session->smb2->nonce_high_random));
  switch (conn->smb2.server.cipher) {
  case SMB2_ENCRYPTION_AES128_CCM:
    nonce_size = SMB2_AES_128_CCM_NONCE_SIZE;
    break;
  case SMB2_ENCRYPTION_AES128_GCM:
    nonce_size = gnutls_cipher_get_iv_size(GNUTLS_CIPHER_AES_128_GCM);
    break;
  case SMB2_ENCRYPTION_AES256_CCM:
    nonce_size = SMB2_AES_128_CCM_NONCE_SIZE;
    break;
  case SMB2_ENCRYPTION_AES256_GCM:
    nonce_size = gnutls_cipher_get_iv_size(GNUTLS_CIPHER_AES_256_GCM);
    break;
  default:
    nonce_size = 0;
    break;
  }
  session->smb2->nonce_high_max = SMB2_NONCE_HIGH_MAX(nonce_size);
  session->smb2->nonce_high = 0;
  session->smb2->nonce_low = 0;

  return NT_STATUS_OK;
}

NTSTATUS smb2cli_session_create_channel(TALLOC_CTX *mem_ctx,
          struct smbXcli_session *session1,
          struct smbXcli_conn *conn,
          struct smbXcli_session **_session2)
{
  struct smbXcli_session *session2;
  NTSTATUS status;

  if (!smb2_signing_key_valid(session1->smb2->signing_key)) {
    return NT_STATUS_INVALID_PARAMETER_MIX;
  }

  if (conn == NULL) {
    return NT_STATUS_INVALID_PARAMETER_MIX;
  }

  session2 = talloc_zero(mem_ctx, struct smbXcli_session);
  if (session2 == NULL) {
    return NT_STATUS_NO_MEMORY;
  }
  session2->smb2 = talloc_reference(session2, session1->smb2);
  if (session2->smb2 == NULL) {
    talloc_free(session2);
    return NT_STATUS_NO_MEMORY;
  }

  talloc_set_destructor(session2, smbXcli_session_destructor);
  DLIST_ADD_END(conn->sessions, session2);
  session2->conn = conn;

  status = smb2_signing_key_sign_create(session2,
                conn->smb2.server.sign_algo,
                NULL, /* no master key */
                NULL, /* derivations */
                &session2->smb2_channel.signing_key);
  if (!NT_STATUS_IS_OK(status)) {
    talloc_free(session2);
    return NT_STATUS_NO_MEMORY;
  }

  memcpy(session2->smb2_channel.preauth_sha512,
         conn->smb2.preauth_sha512,
         sizeof(session2->smb2_channel.preauth_sha512));

  *_session2 = session2;
  return NT_STATUS_OK;
}

NTSTATUS smb2cli_session_set_channel_key(struct smbXcli_session *session,
           const DATA_BLOB _channel_key,
           const struct iovec *recv_iov)
{
  struct smbXcli_conn *conn = session->conn;
  uint8_t channel_key[16];
  NTSTATUS status;
  struct _derivation {
    DATA_BLOB label;
    DATA_BLOB context;
  };
  struct {
    struct _derivation signing;
  } derivation = {
    .signing.label.length = 0,
  };

  if (conn == NULL) {
    return NT_STATUS_INVALID_PARAMETER_MIX;
  }

  if (smb2_signing_key_valid(session->smb2_channel.signing_key)) {
    return NT_STATUS_INVALID_PARAMETER_MIX;
  }

  if (conn->protocol >= PROTOCOL_SMB3_11) {
    struct _derivation *d;
    DATA_BLOB p;

    p = data_blob_const(session->smb2_channel.preauth_sha512,
        sizeof(session->smb2_channel.preauth_sha512));

    d = &derivation.signing;
    d->label = data_blob_string_const_null("SMBSigningKey");
    d->context = p;
  } else if (conn->protocol >= PROTOCOL_SMB3_00) {
    struct _derivation *d;

    d = &derivation.signing;
    d->label = data_blob_string_const_null("SMB2AESCMAC");
    d->context = data_blob_string_const_null("SmbSign");
  }

  ZERO_STRUCT(channel_key);
  memcpy(channel_key, _channel_key.data,
         MIN(_channel_key.length, sizeof(channel_key)));

  session->smb2_channel.signing_key->blob = data_blob_talloc_s(
    session->smb2_channel.signing_key,
    channel_key,
    sizeof(channel_key));
  if (!smb2_signing_key_valid(session->smb2_channel.signing_key)) {
    ZERO_STRUCT(channel_key);
    return NT_STATUS_NO_MEMORY;
  }

  if (conn->protocol >= PROTOCOL_SMB3_00) {
    struct _derivation *d = &derivation.signing;

    status = samba_gnutls_sp800_108_derive_key(
      channel_key,
      sizeof(channel_key),
      NULL,
      0,
      d->label.data,
      d->label.length,
      d->context.data,
      d->context.length,
      GNUTLS_MAC_SHA256,
      session->smb2_channel.signing_key->blob.data,
      session->smb2_channel.signing_key->blob.length);
    if (!NT_STATUS_IS_OK(status)) {
      return status;
    }
  }
  ZERO_STRUCT(channel_key);

  status = smb2_signing_check_pdu(session->smb2_channel.signing_key,
          recv_iov, 3);
  if (!NT_STATUS_IS_OK(status)) {
    return status;
  }

  return NT_STATUS_OK;
}

NTSTATUS smb2cli_session_encryption_on(struct smbXcli_session *session)
{
  if (session->smb2->anonymous_signing) {
    return NT_STATUS_INVALID_PARAMETER_MIX;
  }

  if (session->smb2->anonymous_encryption) {
    SMB_ASSERT(session->smb2->should_encrypt);
    SMB_ASSERT(!session->smb2->should_sign);
    return NT_STATUS_OK;
  }

  if (!session->smb2->should_sign) {
    /*
     * We need required signing on the session
     * in order to prevent man in the middle attacks.
     */
    return NT_STATUS_INVALID_PARAMETER_MIX;
  }

  if (session->smb2->should_encrypt) {
    return NT_STATUS_OK;
  }

  if (session->conn->protocol < PROTOCOL_SMB3_00) {
    return NT_STATUS_NOT_SUPPORTED;
  }

  if (session->conn->smb2.server.cipher == 0) {
    return NT_STATUS_NOT_SUPPORTED;
  }

  if (!smb2_signing_key_valid(session->smb2->signing_key)) {
    return NT_STATUS_NOT_SUPPORTED;
  }
  session->smb2->should_encrypt = true;
  return NT_STATUS_OK;
}

uint16_t smb2cli_session_get_encryption_cipher(struct smbXcli_session *session)
{
  if (session->conn->protocol < PROTOCOL_SMB3_00) {
    return 0;
  }

  if (!session->smb2->should_encrypt) {
    return 0;
  }

  return session->conn->smb2.server.cipher;
}

struct smbXcli_tcon *smbXcli_tcon_create(TALLOC_CTX *mem_ctx)
{
  struct smbXcli_tcon *tcon;

  tcon = talloc_zero(mem_ctx, struct smbXcli_tcon);
  if (tcon == NULL) {
    return NULL;
  }

  return tcon;
}

/*
 * Return a deep structure copy of a struct smbXcli_tcon *
 */

struct smbXcli_tcon *smbXcli_tcon_copy(TALLOC_CTX *mem_ctx,
        const struct smbXcli_tcon *tcon_in)
{
  struct smbXcli_tcon *tcon;

  tcon = talloc_memdup(mem_ctx, tcon_in, sizeof(struct smbXcli_tcon));
  if (tcon == NULL) {
    return NULL;
  }

  /* Deal with the SMB1 strings. */
  if (tcon_in->smb1.service != NULL) {
    tcon->smb1.service = talloc_strdup(tcon, tcon_in->smb1.service);
    if (tcon->smb1.service == NULL) {
      TALLOC_FREE(tcon);
      return NULL;
    }
  }
  if (tcon->smb1.fs_type != NULL) {
    tcon->smb1.fs_type = talloc_strdup(tcon, tcon_in->smb1.fs_type);
    if (tcon->smb1.fs_type == NULL) {
      TALLOC_FREE(tcon);
      return NULL;
    }
  }
  return tcon;
}

void smbXcli_tcon_set_fs_attributes(struct smbXcli_tcon *tcon,
            uint32_t fs_attributes)
{
  tcon->fs_attributes = fs_attributes;
}

uint32_t smbXcli_tcon_get_fs_attributes(struct smbXcli_tcon *tcon)
{
  return tcon->fs_attributes;
}

bool smbXcli_tcon_is_dfs_share(struct smbXcli_tcon *tcon)
{
  if (tcon == NULL) {
    return false;
  }

  if (tcon->is_smb1) {
    if (tcon->smb1.optional_support & SMB_SHARE_IN_DFS) {
      return true;
    }

    return false;
  }

  if (tcon->smb2.capabilities & SMB2_SHARE_CAP_DFS) {
    return true;
  }

  return false;
}

uint16_t smb1cli_tcon_current_id(struct smbXcli_tcon *tcon)
{
  return tcon->smb1.tcon_id;
}

void smb1cli_tcon_set_id(struct smbXcli_tcon *tcon, uint16_t tcon_id)
{
  tcon->is_smb1 = true;
  tcon->smb1.tcon_id = tcon_id;
}

bool smb1cli_tcon_set_values(struct smbXcli_tcon *tcon,
           uint16_t tcon_id,
           uint16_t optional_support,
           uint32_t maximal_access,
           uint32_t guest_maximal_access,
           const char *service,
           const char *fs_type)
{
  tcon->is_smb1 = true;
  tcon->fs_attributes = 0;
  tcon->smb1.tcon_id = tcon_id;
  tcon->smb1.optional_support = optional_support;
  tcon->smb1.maximal_access = maximal_access;
  tcon->smb1.guest_maximal_access = guest_maximal_access;

  TALLOC_FREE(tcon->smb1.service);
  tcon->smb1.service = talloc_strdup(tcon, service);
  if (service != NULL && tcon->smb1.service == NULL) {
    return false;
  }

  TALLOC_FREE(tcon->smb1.fs_type);
  tcon->smb1.fs_type = talloc_strdup(tcon, fs_type);
  if (fs_type != NULL && tcon->smb1.fs_type == NULL) {
    return false;
  }

  return true;
}

uint32_t smb2cli_tcon_current_id(struct smbXcli_tcon *tcon)
{
  return tcon->smb2.tcon_id;
}

void smb2cli_tcon_set_id(struct smbXcli_tcon *tcon, uint32_t tcon_id)
{
  tcon->smb2.tcon_id = tcon_id;
}

uint32_t smb2cli_tcon_capabilities(struct smbXcli_tcon *tcon)
{
  return tcon->smb2.capabilities;
}

uint32_t smb2cli_tcon_flags(struct smbXcli_tcon *tcon)
{
  return tcon->smb2.flags;
}

void smb2cli_tcon_set_values(struct smbXcli_tcon *tcon,
           struct smbXcli_session *session,
           uint32_t tcon_id,
           uint8_t type,
           uint32_t flags,
           uint32_t capabilities,
           uint32_t maximal_access)
{
  tcon->is_smb1 = false;
  tcon->fs_attributes = 0;
  tcon->smb2.tcon_id = tcon_id;
  tcon->smb2.type = type;
  tcon->smb2.flags = flags;
  tcon->smb2.capabilities = capabilities;
  tcon->smb2.maximal_access = maximal_access;

  tcon->smb2.should_sign = false;
  tcon->smb2.should_encrypt = false;

  if (session == NULL) {
    return;
  }

  tcon->smb2.should_sign = session->smb2->should_sign;
  tcon->smb2.should_encrypt = session->smb2->should_encrypt;

  if (flags & SMB2_SHAREFLAG_ENCRYPT_DATA) {
    tcon->smb2.should_encrypt = true;
  }
}

void smb2cli_tcon_should_sign(struct smbXcli_tcon *tcon,
            bool should_sign)
{
  tcon->smb2.should_sign = should_sign;
}

bool smb2cli_tcon_is_signing_on(struct smbXcli_tcon *tcon)
{
  if (tcon->smb2.should_encrypt) {
    return true;
  }

  return tcon->smb2.should_sign;
}

void smb2cli_tcon_should_encrypt(struct smbXcli_tcon *tcon,
         bool should_encrypt)
{
  tcon->smb2.should_encrypt = should_encrypt;
}

bool smb2cli_tcon_is_encryption_on(struct smbXcli_tcon *tcon)
{
  return tcon->smb2.should_encrypt;
}

void smb2cli_conn_set_mid(struct smbXcli_conn *conn, uint64_t mid)
{
  conn->smb2.mid = mid;
}

uint64_t smb2cli_conn_get_mid(struct smbXcli_conn *conn)
{
  return conn->smb2.mid;
}

NTSTATUS smb2cli_parse_dyn_buffer(uint32_t dyn_offset,
          const DATA_BLOB dyn_buffer,
          uint32_t min_offset,
          uint32_t buffer_offset,
          uint32_t buffer_length,
          uint32_t max_length,
          uint32_t *next_offset,
          DATA_BLOB *buffer)
{
  uint32_t offset;
  bool oob;

  *buffer = data_blob_null;
  *next_offset = dyn_offset;

  if (buffer_offset == 0) {
    /*
     * If the offset is 0, we better ignore
     * the buffer_length field.
     */
    return NT_STATUS_OK;
  }

  if (buffer_length == 0) {
    /*
     * If the length is 0, we better ignore
     * the buffer_offset field.
     */
    return NT_STATUS_OK;
  }

  if ((buffer_offset % 8) != 0) {
    /*
     * The offset needs to be 8 byte aligned.
     */
    return NT_STATUS_INVALID_NETWORK_RESPONSE;
  }

  /*
   * We used to enforce buffer_offset to be
   * an exact match of the expected minimum,
   * but the NetApp Ontap 7.3.7 SMB server
   * gets the padding wrong and aligns the
   * input_buffer_offset by a value of 8.
   *
   * So we just enforce that the offset is
   * not lower than the expected value.
   */
  SMB_ASSERT(min_offset >= dyn_offset);
  if (buffer_offset < min_offset) {
    return NT_STATUS_INVALID_NETWORK_RESPONSE;
  }

  /*
   * Make [input|output]_buffer_offset relative to "dyn_buffer"
   */
  offset = buffer_offset - dyn_offset;
  oob = smb_buffer_oob(dyn_buffer.length, offset, buffer_length);
  if (oob) {
    return NT_STATUS_INVALID_NETWORK_RESPONSE;
  }

  /*
   * Give the caller a hint what we consumed,
   * the caller may need to add possible padding.
   */
  *next_offset = buffer_offset + buffer_length;

  if (max_length == 0) {
    /*
     * If max_input_length is 0 we ignore the
     * input_buffer_length, because Windows 2008 echos the
     * DCERPC request from the requested input_buffer to
     * the response input_buffer.
     *
     * We just use the same logic also for max_output_length...
     */
    buffer_length = 0;
  }

  if (buffer_length > max_length) {
    return NT_STATUS_INVALID_NETWORK_RESPONSE;
  }

  *buffer = (DATA_BLOB) {
    .data = dyn_buffer.data + offset,
    .length = buffer_length,
  };
  return NT_STATUS_OK;
}

struct smbXcli_session_dump_cp_state {
  char *s;
};

static void smbXcli_session_dump_keys_cb(const char *buf, void *private_data)
{
  struct smbXcli_session_dump_cp_state *state = private_data;

  talloc_asprintf_addbuf(&state->s, "%s", buf);
}

void smbXcli_session_dump_keys(uint64_t session_id,
             DATA_BLOB *session_key,
             uint16_t signing_algo,
             DATA_BLOB *signing_key,
             DATA_BLOB *application_key,
             DATA_BLOB *encryption_key,
             DATA_BLOB *decryption_key,
             const char *wireshark_keyfile)
{
  struct smbXcli_session_dump_cp_state state = {
    .s = talloc_strdup(talloc_tos(), ""),
  };
  DATA_BLOB sidb = {
    .data = (uint8_t *)&session_id, .length = sizeof(session_id)
  };
  char *line = NULL;
  int fd = -1;
  ssize_t written;

  talloc_asprintf_addbuf(&state.s, "debug encryption: dumping generated session keys\n");
  talloc_asprintf_addbuf(&state.s, "Session Id    ");
  dump_data_cb((uint8_t*)&session_id,
         sizeof(session_id),
         false,
         smbXcli_session_dump_keys_cb,
         &state);
  talloc_asprintf_addbuf(&state.s, "Session Key   ");
  dump_data_cb(session_key->data,
         session_key->length,
         false,
         smbXcli_session_dump_keys_cb,
         &state);
  talloc_asprintf_addbuf(&state.s, "Signing Algo: %u\n", signing_algo);
  talloc_asprintf_addbuf(&state.s, "Signing Key   ");
  dump_data_cb(signing_key->data,
         signing_key->length,
         false,
         smbXcli_session_dump_keys_cb,
         &state);
  talloc_asprintf_addbuf(&state.s, "App Key       ");
  dump_data_cb(application_key->data,
         application_key->length,
         false,
         smbXcli_session_dump_keys_cb,
         &state);

  /* In client code, ServerIn is the encryption key */

  talloc_asprintf_addbuf(&state.s, "ServerIn Key  ");
  dump_data_cb(encryption_key->data,
         encryption_key->length,
         false,
         smbXcli_session_dump_keys_cb,
         &state);
  talloc_asprintf_addbuf(&state.s, "ServerOut Key ");
  dump_data_cb(decryption_key->data,
         decryption_key->length,
         false,
         smbXcli_session_dump_keys_cb,
         &state);

  talloc_asprintf_addbuf(&state.s, "Wireshark configuration line:\n");
  line = talloc_asprintf(
    talloc_tos(),
    "%s,%s,%s,%s\n",
    data_blob_hex_string_lower(state.s, &sidb),
    data_blob_hex_string_lower(state.s, session_key),
    data_blob_hex_string_lower(state.s, decryption_key),
    data_blob_hex_string_lower(state.s, encryption_key));
  if (line == NULL) {
    goto done;
  }
  talloc_asprintf_addbuf(&state.s, "%s", line);

  DEBUG(0, ("%s", state.s));

  if (wireshark_keyfile == NULL) {
    goto done;
  }
  fd = open(wireshark_keyfile, O_WRONLY | O_APPEND);
  if (fd == -1) {
    DBG_ERR("Failed to open '%s': %s\n",
      wireshark_keyfile, strerror(errno));
    goto done;
  }

  written = write(fd, line, strlen(line));
  if (written != strlen(line)) {
    DBG_ERR("Failed to write '%s' to '%s', only wrote: %zd\n",
      line, wireshark_keyfile, written);
    goto done;
  }

done:
  TALLOC_FREE(line);
  TALLOC_FREE(state.s);
  if (fd != -1) {
    close(fd);
  }
}

Coverage Report

Created: 2026-04-01 06:26